To my knowledge (which might contain large gaps, so keep that in mind) there are a few basic options that are regularly put into Strads coming off of the line:
Bores: ML and L are the most common but M is not unheard of
Bells: 37, 43, 25 (Found usually on the L bore models) 72, 65
Tuning slide: Standard and reversed
Finishes: Silver plated and lacquered
Actually, rather than letting me blather on about a subject that I admittedly only know a bit about, you would probably be better served by digesting some of the info on this site, dedicated specifically to Bach Strad trumpets:
http://www.thebachloyalist.freeserve...ewtrumpet.html
Good luck!
