@ Hammie - You're not going to find a lot of action for the bigger Boulevards on this forum. Here is a link to the the C109 discussions in the forums at m109riders.com: C109Riders There is a ton of good information there and Gman is a regular (his products rock, btw).
The quick answer about the surging is it's caused by the bike having retarded timing and running very lean, especially in the lower gears. The combination of a TRE and a fuel processor (like The Bully) helps a lot. The TRE fools the computer into thinking you're in 4th during gears 1-3, advancing the timing in those gears back to normal. A fuel processor helps overcome the lean condition. The Bully is the only fuel processor I'm aware of that you can adjust your mixtures on the fly. Hope this gets you started. Good choice on the bike!