If you are going to look at a custom Bushy take a look at the Venom as well (http://www.zenitram-mfg.com/
). It has more upgrades then the Shocktech (at a higher price though). Neither come with a barrel but the Venom now has the MacDev Gladiator with it. They are both nice looking markers. Venom also give you options of mid or high rise, blade or curved trigger, 45 or z-grip frame along with those upgraded parts.
If you want to save some money just get a 2K3/PDS and then do you own upgrades as your budget allows. I thought I read they were going to start using cocker threads standard on the newest 2K3's. However the LCD is not a standard option anymore if you want that.
Mine had really bad blowback so I had to get a Vapor bolt but they are only like $30.