Again, thanks for your replies!
I went to the Triumph dealer at the weekend and it very much looks like the Street Triple is out of the questions. It's far far too big.
Minnie, I definitely have the same problem!
I'm not considering the Ninja 250. Don't know much about them though except that they wouldn't take that much lowering.
Ghosthunter, thanks for the lovely offer, but I think I'll keep my legs as they are!