What do you mean by cams w/b? You can't use the old non-roller cams in the roller motors. I think some guy in south america tried it and it ran like shiet. JWT is working on a set for the newer motors though.
JWT doesn't have the 99+ ecu's ready yet. ETA end of year
The G20 came with a rocker roller motor starting 2000 model and over. Mines a 99 and has the non-roller rocker motor.