The only hammer kits available today that will work with these bodies are the super expensive, but insanely nice REX sidewinder hammer kit from Belsales (available from CompulsivePaintball.com), the AKA kits (from their site) and I think ANS has a rip-off of the rex kit. I have one, but it doesn't adjust. I ended up using the hammer and an old sheridan adjuster in my Sniper.
You can find the AKA kits for fairly cheap, but if you want something with good adjustablility and a very smooth kit, go with Belsales.
Bleeding Paint and Sweating CO2 since 1988!