To the OP - how many spoke holes are there on your current hub?
Like DieselDan said, your best option is to get a new hub with 40, or 40+ holes and take it from there.
FWIW I weigh 265# and I wouldn't use less than 36 spokes on my 700C bike. 400# is way too much for 32 spokes, even with 26 inches.
Only problem with going for 40+ spokes may be rim availability. I'm guessing your choices may be more restricted, but it would still be worthwhile.
A cheap alternative might be to keep an eye out on Craigs List for a used 8 speed mtb with a 36 spoke wheel. You may well be able to buy the whole bike for a lot less than getting a wheel built. Transfer the 36 spoke wheel to your bike and Ebay the usable components from the donor bike, or just put the repaired 32 spoke wheel in it and sell it complete.