The 2006 Speed Four should have already come with a 15 tooth front sprocket and a 45 tooth rear sprocket from the factory. The chain length is indeed 108 links and 525 for this setup. A TT600 and Speed Four sprocket are exactly the same. The rear sprocket for a Suzuki GSXR600 '01-'05 are the same as well, so that gives you a good amount of options.
I've used JT Sprockets in the past. Model #1792.45
Im using a Drive Systems sprocket now. (AFAM #14604)
I've had good luck with both so far.
A while ago it seemed that the Monstrack mirrors were the hot item for those that wanted regular style handlebar mounted mirrors.
http://www.monstrack.com/mirrors.html
Can't help you on the levers or the mapping.