The best I have seen on the market is the ISIS. It has a completely new housing, and is very easy to install. It is cheaper than the B&M and does not have rattle at high rpms. ISIS is a new company and is now being recognized for having very solid products. Give them a try and you will not be disappointed.
Hint: NEVER take the shifter off the bass B&M provides. If you do it will never shift the same again. ALWAYS remove the assembly, plate and shifter, as one unit. :-)