Here's what I'm using for anti-fog on my Rift. Simple aquarium pump... about $15 from Walmart. I didn't have any Zip-ties so just used twist ties to attach the neoprene tube to the feed wire. It's pretty low pressure and CFM but it's enough to eliminate the fogging problem that I had. I would like a bit more pressure and CFM... maybe an airbrush compressor? But this is really quiet and does the job. I can't feel the tube where it goes between the foam cushion.
Crude... but it's eliminated the fogging frustration (guess I'm a sweathog ).