Funny enough I ran into the same issue today. No name aftermarket AutoFX seats, way too high. My fab guy is also going to cut down my brackets to fit them. Looking at mine with the FX seats, they're bolstered under the thigh, whereas the Jeep seats are flat and it's the bracket that puts the seat on the comfortable angle. We're going to eliminate that angle. Drivers mount is non-flip, so it'll just get cut with ~2-3" out of the front "legs", weld back together. Flip-forward passenger seat is a little more complicated. Cross bar will be cut, then front legs shortened 2-3". Cross bar will get lapped and welded again. Rear of that mount should be able to be left alone.
I'm also considering moving the rear seat back 2-3" for leg room. Preferably be able to weld in nuts so I can choose forward or back by just moving the 2 brackets. There's practically no cargo space with the seat installed anyway... might as well get my little guy's legs out of my seats.
'91 Frankenheep YJ. 4.0, 4" BDS, Richmond 8.8, Titan 12k, 35" KM2's, rust.
'88 YJ, 4.2/4.0 head, +4½" & shackles, BFG 33's (sold)