http://www.tonystrains.com/products/qsi_solutions_main.htm
Figure about $100 for the decoder and $80 for the programmer.
The installation should be pretty easy. The QSI Quantum Revolution board should drop right in and the BLI AC6000 mounts the speakers in the fuel tank.
When you install the speakers and try it, it won't sound like much withh the body off. I bought an undecorated BLI AC6000 on a closeout and have the body off to paint and letter. The sound level drops significantly without the body. With it on, so it's properly baffled, it sound great.