I have a set of these Mugen covers
Mugen Leather Seat Covers with matching door panels, steering wheel, gear shift and hand brake.
I think to modify the passenger drivers seat to up/down adjustable, you may only need the frame and plastic trimmings from a UK or Asian wreck.
Update:
Ok I just had a quick look at the floor in my right hand drive fit and it seems the drivers side floor fitting and shape are different from the passenger side.