Personally I wouldnt buy any of the JT Autocockers (trilly/SR).
If your buddy knows NOTHING about autocockers then the trilly WOULD be the best bet as it was designed to be almost idiot proof, for anyone who knows how to use and time an autococker, there are better options out there.
Im not really a fan of anything past 05 either though so I am a bit bias.
Easy way to tell a trilly and SR apart from the rest. Trilly has a built in 3way on the ASA, center mounted LPR, and a totally rounded body. The SR has the uni-block front end that is a massive enclosure for the noid, LPR and Ram. It also has a vertical frame with a hump, it is midblocked (no back block), and has big black sail-wings on the sides to hide the eyes and pump arm.
For the money you are looking at for those two, you can get a real autococker with better parts.