A racing seat is not really a chair. It is the fixed reference point that everything else in the rig is measured from, and its job is to stop moving while the wheel base tries to twist it. That is why a castored office chair falls apart as a sim solution the moment torque arrives: it rolls back under braking, and your distance to the pedals changes lap by lap.

Match the frame to the wheel base you own or plan to buy. Folding wheel stands cope with belt-driven wheels and entry direct drive to roughly 10Nm. Welded steel cockpits hold their shape to around 18Nm. Beyond that, T-slot aluminium profile is what keeps 25Nm and above from being absorbed by frame flex before it reaches your hands. Evetech carries the wheels and pedals to go with them, from Logitech and Thrustmaster through to Fanatec and MOZA direct drive.