I can see where the original poster is coming from, he'd rather not get a 737/A320 TR like everybody else as it looks a little over crowded in the holding pools.
Gaining a 757/767 TR will appeal to the medium haul ops but as said above it's unlikely that you'll pull that one off, I think a few carriers and getting rid of the 757's anyhow.
If I am forced / feel pressured to getting a SSTR I'd probably look toward the TP AC's, Cheaper TR (£15k ish for the Dash 8 / ATR 42 or 72 / Saab 340) and better job prospects of landing a TP job should you have 500+hrs on your log book.
Good luck.