I use the 41700, 17" hip width, Kirkey Pro Street seat. I use the 41711 cover. Much better than the plastic seat that was in the K. Plus I needed to sit lower to get below the cage. I am 6' 1" 250lbs, mostly belly.

Walter
1969 Dart Swinger w/ARC Pump Gas 493 B1/BS 10.18 at 130mph
Racing Pro in street trim.
1981 Aries ARC 548 B1 8.88 at 147mph (footbraking)
1996 Ram 2500 V10 16.52 at 80mph
1981 Reliant 400