I pick up my 07 Bonneville T100 this coming Saturday. I went with the British Custom Predator pipes, rejetted carbs, K&N filters and removed the oxygen sensor and airbox. As time goes by I may do some more changes, probably the suspension. Thanks for the info. Looking forward to putting some miles on it.I put about 10k miles on an '06 T100 and I put around 2.5k on an '05 Thruxton. They're fine good handling reliable bikes, tons of fun to ride. I sold mine because I'm on the large side and fit my Dyna better but the Bonnie remains one of my favorite bikes.
Stock they're corked up pretty good with typical EPA pipes and jetting however a few bucks well spent wakes them right up. On mine I added Triumph Off Road pipes or TOR's, these come with the appropriate jets, I also drilled the slide relief hole out to 8mm and added a K&N stock replacement air filter and a Norman Hyde Intake Bellmouth, this allows you to retain the stock airbox for the rain, but still breathe better. I also added some Hagon Progressive wound fork springs, 20wt Fork oil and Hagon Nitro rear shocks along with a leather Corbin Canyon Duel seat.
There's a pretty healthy aftermarket for all kinds of performance and handling add ons almost rivaling Harley in scope. A lot of it is based in England like Norman Hyde or France like Mecatwin but it's all readily available here in the US and there's a few US suppliers like NewBonneville.com that carry a pretty extensive catalog.
All in all they're excellent bikes stock and easily tweaked if you want to, Highly recommended.