I like the 22x8 the best on my BME 50. I am using MSC props, they will give a bit lower RPM's but the pulling power is awesome, it seems as though they are like the Bambula's. I think any GOOD 22x8 will do it, some people like the 22x10. I tried both and just liked the feel of the 8 pitch better.
http://www.mscprops.com/
http://www.troybuiltmodels.com/Propellers.html
http://www.aircraftinternational.com/
Almost forgot, break-in. My intention was to break it in on the 22x8 and then switch to the 10 pitch, but as you can see that didn't come about, I just stayed with the 8.