There are replacement parts and I did not know if it would be possible to adapt it to connect to the steam deck.
https://www.amazon.com/Game-Card-Reader-Compatible-Nintendo-Switch/dp/B088Y77WYH
I saw this case on amazon, looks a lot like yours
A micro SD card is not really going to have massive power differences between brands. It really depends on how much you are willing to spend.
1 TB Extreme MicroSD seems to be pretty much the largest and fastest you can get, for about $170.
1 TB Ultra MicroSD is the same size, but slower speed storage option, for about $125
Besides that, you have all the regular options for each type, 512 GB, 256 GB, 128 GB, and so on if you are on a tighter budget. Though, reading a little about the limitations on the Deck, it may have a limit on MicroSD transfer rate, like possibly 104MB/s, so they Ultra might be a more practical choice, just because its transfer rate is closer to the UHS-1 (Ultra 120 MB/s vs Extreme 160 MB/s), so less wasted money, but I am uncertain, and hope that someone more knowledgeable can confirm or deny that.
I just looked and the cheapest I found on Amazon is
1TB M2 $115 https://www.amazon.com/gp/product/B0B1WM5PQ7/ref=ox_sc_saved_image_1?smid=A3BTFWKGLBT0VA&psc=1
SanDisk 1TB sd card $164 https://www.amazon.com/gp/product/B0892218X7/ref=ox_sc_saved_image_3?smid=AK0X39W9935WX&psc=1
I agree. My main goal with my steam deck is to make a second screen that attaches to the top, sort of like a Nintendo DS (to be used for emulating games). Making a cool dock to stick next to my computer, even if it’s just for charging, would be very fun!
Something you could use instead of a 3d printer for small projects is pla sheet/plate. It’s readily available on Amazon or hobby stores at relatively low cost. PLA (polylactic acid) is the most common type of plastic used for 3d printing and is very easy to work with in both sheet and 3d printed form. It would take a decent amount of work and hot glue but you could definitely make something like what you’re describing with this stuff and some paint!
This is an example of it - Pla Plate Set (Three Types/Five Sheets) https://smile.amazon.com/dp/B001Q16LQY/ref=cm_sw_r_cp_api_glt_i_B84XG6VKF3XP19E4EYTC