Question about Pimax 8K

You still need at least 1 better 2 SteamVR Base Station

HTC Vive SteamVR Base Station 2.0

And 2 matching controllers (for VR interaction):

HTC Vive Controller
Or
HTC Vive Controller 2.0

If you "only" want to play DCS or racing simulation, then you don't necessarily need the controllers, a HOTAS is also sufficient, e.g.

Thrustmaster TM Hotas Warthog Joystick, PC
(there are also cheaper ones :) )

or a control wheel, e.g.
Logitech G G920 Driving Force

2x HTC Vive Base Station 2.0
2x HTC Vice Controller 2.0 or 2x Steam Valve Index Controller (if you get them)
In your PC you need at least a Nividia RTX 2070, but a RTX 2080 is probably better.

I would be careful with AMD. Because these cards are not officially supported by PIMAX.
In any case, my PAMAX runs with the AMD Readon RX 5700, but not optimally. For many games, I have to reduce the viewing area.