A 20" un-dished IGH wheel would be totally bombproof for the OP's weight and would provide maintenance free operation. As other folks have pointed out a custom BF will not be the lowest cost option in terms of upfront purchase, but looking back after 10yrs the cost may be well worth it.

I started with a Dahon Speed D7 and ended up with a Tikit at twice the price. 4 years later the Tikit was a better deal on any evaluation criteria [cost/KM or cost/smile].