I am close now a bit over 350#; and dropping fast since New Years.
I build my own wheels after becoming very frustrated with a LBS.
I use Wheelmaster 40h Tandem hubs, which are 100mm OLD in front and 135mm OLD in rear.
http://www.amazon.com/WheelMaster-Al...bxgy_sg_text_y
http://www.amazon.com/HUB-RR-MT1110-...wheelmaster+40
They are also available in silver.
Wheelsmith SS14 (Ø2.0mm) spokes
Velocity Dyad rims for 622 (700c) and Velocity Aerohead rims for 559 (26").
These hubs are a copy of Phil Wood's design. A 5mm Allen Key is all that is required to take the rear hub apart. They use industrial style cartridge bearings and roll nicely.
I currently have wheelsets like this that I built on our tandem (500++ lbs team) and my two commuter bikes. No issues.
You could also purchase these, which use the hubs above:
http://www.amazon.com/Wheel-Master-S...wheelmaster+40
I would tension and stress relieve the spokes.
They are not disc compatible.