it's actually easier to modify the stock power seats then to fucc with the knee bolster. remove driver side seat, then get a spot weld drill and take out the stamped-steel blocks under the rear seat mount, also have to peel away some carpet foam under seat, this will gain you a lot more room, and let you sit lower in the car.

if that's not enough, get the Base model seats, they don't have all the power motors under the chair, so they should drop lower.