back to the drawing board...the pain of shimano

Given it's a MTB frame, I'd be concerned about whether generic fixie cranks would clear the chainstays.

If you choose MTB cranks, you should get a chainline that allows you to use a proper 135mm singlespeed hub in the future.

Hmm...the friends using them, have them on old MTB frames.

You think MTB cranks are a much better option? They seem to be pretty expensive...although I am sorely tempted by those Zee ones...