I'm only half understanding this. It seems like you want a "bike" set up. Hand clutch, foot shift. No problem, go for it. Clamp the clutch handle to your steering wheel, around the 9 or 10 o'clock position. For the shifter, you'll have to fabricate a linkage to the transmission. Still not getting the spring thing. If your linkage moves freely, I don't think it would be necessary. If you do want a spring return, you'd need two, as the shift must be returned to "centre".
To eliminate unintended shift, set up the shifter a little too far to the left (or right) of where your foot would normally rest. If you have to deliberately move your foot into position, it shouldn't happen by accident.