> At the moment I try to get 270 and 360 steeringwheels in one single mechanism and it seems that there are people who did it more or less good...
I'm not aware of that being possible, mechanically.
360 steering wheels are essentially spinners.
270 steering wheels are essentially potentiometers.
IIRC mame allows some games to use digital inputs to simulate analog controls to some degree, by choosing which key increases the steer, and which decreases it... making analog games moderately playable with digital controls, but I've tried in vein to play spy hunter like that and found it worthless... I had to wait two years for my steering yoke to arrive before that game became playable to me.
If driving games are really the priority here, and you have five control panels... make one with 360 wheels, and one with potentiometer wheels.
You had said something about a motorcycle handlebar panel... that handlebar would probably be a potentiometer 270 wheel anyway, so I think you're pretty much there. The decision is what shape that wheel is in... a steering wheel, a handle bar, a yoke, or a fish. If you go yoke, try to go star wars yoke, which gives you a y axis control and several buttons as well. Its what I did.
I have a sub hunt yoke I could part with if you need it... it's identical to the star wars yoke, just a different decal. You can also get a brand new star wars yoke from ram controls but beware... I waited over two years for mine to ship from there... and west controls has brand new ones too but at $500 smackers, they charge a premium price. Correction, they raised their price to $624.