At the weight you've mentioned, I would think a pair of 90mm fans are in order. 29 oz/sq.ft. wing loading is where the big dogs play. I'm partial to twin EDF's but I'm still mucking around with 68mm fans so I can't be much help.

gunradd is correct. Head over to RCG's EDF forum. The very best of the EDF-ers hang out there and will point you in the right direction.