The most popular have been the M75 65w and the BM75 65w speakers in 16 ohm. The BH75/H75 speakers sound good with the BE as well, but most players are looking for a really strong midrange tone with the BE amps.
If you're looking for more low mid emphasis, go with the M75 65w versions. If you're looking for a little more aggressive upper mid cut, and tiny bit more volume, then go with the BM75's.
Hope that helps!
Jim