I looked at each of these setups extensively over the past few months and finally got the Marada racing seat from Amazon for Christmas.
I mounted a Subaru seat which is very comfortable but makes the whole setup very heavy to move around (and the seat is not easily removable). I’ve only used it a handful of times but I’m happy with it so far.
I just picked up a nice adjustable rig (with no seat, have my own) from Amazon for $145 shipped.
Edit: added link
The frame is something i bought on amazon, $140 it. Made out of steel square tubing. The pedals are sturdy but the wheel arms sway left and right. Should be easy to make two brackets or plates to stiffen it up. It does have bolt cutouts for the g920 and other wheels it looks like.
https://www.amazon.com/gp/product/B07NVDKWLY/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
I also needed to extend it because im tall (6'2" for reference) its a easy fix though. There are two 1x1 tube steel pieces that connect the seat rail with the rest of the rig. I stole two 1x1x1/16 aluminum L bracket from work, cut them to 19 inches and slit them in. they are the unpainted aluminum in the photos above. But for the money its a good rig. i think at least.