Thanks. Looking around more it seems Niagara has lots of options, although not that much info on them and they seem quite generic

http://www.niagaracycle.com/index.php?cPath=404_135_197

Nashbar has a $30 front disc MTB wheel (just went up $5, used to be $25) but not much info on the width.

I think I'm going to go with a standard wider MTB rim wheelset that is disc + rim brake compatible since the point of using the 26" MTB is for worst weather conditions anyway. I found a Deore/Sun Rhyno Lite set on jenson for <$100

My 1.95 tires probably shouldn't be on my 20mm rims to begin with (even though that was the stock setup). This way I can switch out my existing front wheel as either a 1.25 using rim brakes, or the fatter tire with disc brakes once I fit those. The rear I'll just keep as is, and change the tire as I need to. The current rear wheel has a freewheel so the drivetrain is probably not compatible with any new rear wheel I buy. The new rear wheel I can keep around until I feel like upgrading more (new cassette, and possibly rear disc brake).