Ok gang, bargain shopping time.

I'm looking at building up a fixed/free mtb wheel (no, for serious--the free is for off-road the fixed is for getting there) and I'm torn between a Surly and Kogswell hub.

The Kogswell is $80 for front and rear and includes free shipping. It comes fixed/fixed so I could conceivably use a track cog on both sides and have a fixed road gear and fixed off road.

On the other hand, I don't need a front, really. I'm also concerned that fewer engaged threads may cause the freewheel to strip the hub even though that's not the case with a track cog that has the same number of engaged threads.

My LBS can get me the Surly for $70, rear only. It's a fixed/free but that's my intention.

What should I do?