Monoprice Above Fireplace Pull-Down Full-Motion Articulating TV Wall Mount Bracket For TVs 55in to 100in, Max Weight 154lbs, VESA Patterns Up to 800x600, Rotating, Height Adjustable Black https://www.amazon.com/dp/B077YB196D/ref=cm_sw_r_cp_api_glt_fabc_N10KEGABA7H8MBJ9SXD8
OLED is the best picture quality available today.
For mounting, going above the fireplace is far from ideal for a comfortable viewing experience, however, that's why mounts like this exist.
You simply pull the TV down to your viewing height when you want to, and then just put it back up when you don't want it to be intrusive. Don't bother with the GX, it's overpriced and from what I'm seeing, you won't be able to take advantage of its ergonomics (what you're paying for over the CX).
As far as heat goes, I don't think you will need to worry at all. I have a gas fireplace and like you said, it's just for show, it doesn't really output nearly enough heat for it to make me worry.
Unfortunately a lot of rooms are designed around the fireplace, and there's not a great place to put the TV.
There are wall mounts you can get that you can pull down. Usually they are used for tvs above fireplaces, but I think something this would work perfect for when you're on the couch.
https://www.amazon.com/Monoprice-Fireplace-Pull-Down-Full-Motion-Articulating/dp/B077YB196D
If you want to get a new mount, get something like this and put it above the mantle.
Otherwise you can mount it on the right and just have it at an angle.
Our last house the living room was a lot tighter and the tv was still way up high. It made a huge difference. Definitely recommend it for anyone with a tv over the fireplace Monoprice Above Fireplace Mantel Pull-Down Full-Motion Articulating TV Wall Mount Bracket For LED TVs 55in to 100in, Max Weight 143 lbs, VESA Patterns Up to 800x600, Rotating, Height Adjustable, Black https://www.amazon.com/dp/B077YB196D/ref=cm_sw_r_cp_api_glt_fabc_YCJQX1YXWC7F9EF48XXC
I got this one
Monoprice Above Fireplace Pull-Down Full-Motion Articulating TV Wall Mount Bracket For TVs 55 to 100 inches, Max Weight 154lbs, VESA Patterns Up to 800x600, Rotating, Height Adjustable Black https://www.amazon.com/dp/B077YB196D/ref=cm_sw_r_cp_api_glt_fabc_5M3REAHSDEMDS85SVWRM
Is there enough room above any of the windows to install a height-adjustable TV mount? They make them for installing above fireplaces or anywhere else where the mount needs to be high but you want to view the TV at a lower height. This way you would only be blocking light from the window when you are watching the TV. All other times you could raise it up to minimize the blockage. Something like this.
I had my TV mounted over the fireplace at my last house, but I also had a mount for it that allowed me to lower it whenever the TV was actually in use. Something like this.
If you ever wanna save your neck this pull down TV mount will lower the TV at a better viewing angle and return it to the original height when you're done.
Not sure about 4-5 feet, but they definitely make pulldown mounts designed for above the fireplace
https://www.amazon.com/Monoprice-Fireplace-Pull-Down-Full-Motion-Articulating/dp/B077YB196D
I do this semi-professionally as a side-gig, and have mounted around 250+ TVs in the past few years, including many over fireplaces.
Option A is the best choice. Plywood has higher specific gravity than most wood, meaning that it holds screws better. 3/4 will be plenty for a mount. It well also project the least from your wall, which may or may not be a consideration for you. When you mount the plywood, I recommend spax or a similar brand structural screw. They’re like lag bolts, but they’re skinnier, more resistant to shear damage, often don’t require a pilot hole, and overall just much easier to use because they make a smaller hole in the wall to achieve the same purpose. They are more expensive, but totally worth it.
General rule of thumb is an extension mount doubles the weight of the tv at full extension. Lag bolts in plywood should hold somewhere around 250-300lbs per bolt in 3/4 plywood. I’d put 4 on the top, 2 on the bottom. Anchors are not exactly cumulative, but pretty close. Top anchors will do all of the weight bearing work (cantilever motion), so go strong on the top.
One thing to consider is using a mount like this: Monoprice Above Fireplace Pull-Down Full-Motion Articulating TV Wall Mount Bracket For TVs 55in to 100in, Max Weight 154lbs, VESA Patterns Up to 800x600, Rotating, Height Adjustable https://www.amazon.com/dp/B077YB196D/ref=cm_sw_r_cp_api_i_CURzFb5K6ME87
Reason for that style mount is that a tv over the fireplace is too high (ideal height is middle of the tv at viewer eye level). Over time, a tv located too high can cause neck strain to accumulate.
Do not, under any circumstance mount that tv using only toggle bolts. Even the big ones are rated for at most 265ish lbs; that is a failure rating, safe working load is more like 60-70lbs per anchor. The motion of the tv will cause the mount to saw through the drywall over time, weakening it and eventually busting through; fireplaces are particularly bad because they often have a larger than normal gap between studs, which introduces more flex. Most instructions for extension mounts will say in no uncertain terms to only use on wood studs (plywood is ok) or solid walls (brick, concrete, etc).
Good luck, you sound like you have the right idea!
Every look into a pull down mount if you don't use the fireplace.
You need a pull down mount for the TV like these: https://smile.amazon.com/dp/B077YB196D/
Also look at this. I'm also facing a similar situation.
It'd get a bigger tv. Center it. Use one of those pull down mounts when watching and back up when not.
https://smile.amazon.com/dp/B077YB196D/ref=cm_sw_r_cp_apa_fabc_fRQPFb7N0Q6TD
Obviously if you have more budget you could do A LOT more.
You know they make fireplace pull down mounts, right?
https://www.amazon.com/Monoprice-Fireplace-Pull-Down-Full-Motion-Articulating/dp/B077YB196D