Don't know whether youve seen Boxguy's (I think that's his name... can anyone help me out?) band clamps from those ratchet tie-down bands. He did a great blog on LJ. I made a set, and I'm sure many other members did the same.
You can get great pressure with them... more than those band clamps.
If your first cut is too short... Take the second cut from the longer end... LBD