Several people at my field own GenX3 Cockers at the present moment, and a handful have Kapps, and I've shot both and must say that the GenX's are not only better looking, but have better triggers on them and have fewer leaks among those I have personally shot. The GenX reg is a unireg patterned reg that is easy to work on and is quite reliable over the long haul...having had a Mag earlier it's easy for me to work on in the event of problems, and pretty much everyone around you is going to know how to do them as well.
An alternative is to buy a used Cocker that is partially built up to what you want and add onto it what is missing from your wish list. Examples of such are quite abundant and can usually be found in the neighborhood for $400-500. Hang around local tourneys and I'm pretty sure you can pick one up. Look for deals at local fields too. My personal Cocker runs a Jackhammer pneumatics reg, STO ram, Shocktech bomb, RAT 3:16 valve, Pure Energy vert reg, Benchmark frame, Shocktech superfly bolt, and 14" DYE Ultralite.
Hope this helps!