Just about ANY true race seat (side mount) will be able to be installed to give you the clearance you need. When I mocked up my ultrashield in it's lowest possible position, my eyes were about even with the pony logo on the steering wheel, and I'm 5'11". Best bet is to go with either the Corbeau or Sparco seat bracket, which sits as low in the car as possible, a set of the Sparco side-mount brackets, and then just mount the seat where it needs to be. Focus first on leg position, then on arm position, and those two will determine your seat angle. Tip: Before drilling anything, use an assortment of 2", 1" and 1/2" thick rolls of masking tape to mock up the seat position. Then use a Sharpie to mark the hole locations. IF you do an FIA seat, the holes will be pre-set, and it's just a matter of setting up the brackets to get the position you want. FWIW, the "fabricated" seats, like Ultrashield or Kirkey wind up being about 3/16" thick at the bottom of the seat pan, so no issues with vertical clearance at all.
