Best MTB disc hubs for cyclocross?

Guys, what are the best MTB disc hubs for cyclocross use (not singletrack). I want to run Avis BB7 ROAD brakes with 6 bolt 160mm rotors (also is it possible to use the centerlock Shimano hubs - or are 6 bolt versions required)? I am a fairly heavy guy 220# and don't want to be rebuilding the hubs regularly. I would there to be cheap replacement freehub body parts available though. I am coming from road, and have no experience with the MTB lines. The pre-built disc wheels come with a dizzying number of hub specs! Of these what are people finding are the best option: Shimano XT FH-M756 (older standard w/ 18 clicks) Shimano XT FH-M770 - 36 clicks Shimano XT FH-M775 - 36 clicks Shimano SLX FH-M665 - 32 clicks Shimano SLX FH-M667 - 32 clicks Shimano SLX FH-M629 - 32 clicks Shimano FH-M529 - 16 clicks Shimano FH-M590 - 16 clicks Shimano FH-M595] - 16 clicks (I could care less about # of POE clicks since these are for cyclocross use only). I am leaning towards trying to find wheels that use the Shimano XT FH-M756, since they seem to have a reputation for reliability where the newer FH-M770/5 seem to have issues (especially for heavier riders).