Flew an ARF Helios with a Booster-60 last weekend. Works nicely. Heck, either booster is only $5 at either Wal-Mart or Fred Meyer so give 'em a chance.
Note that they are set up to work with the new ARFs that have the screw-on motor retention caps in each size and that they are for 24mm x 70mm motors (C11, D12). That said, you could also just strip off the bit of body tube at the top of the booster that is the stage coupler and have a nice plastic fin can with a 24mm mount to scratch build either a BT-55 or BT-60 based rocket.