i'd recommend bulletproof cranks and a rocket ring, given your budget. your chainline will be 1.5mm off, but that's not bad. check harris cyclery: http://sheldonbrown.com/harris/crank...ct-double.html for bulletproof info. since there's a 39mm chainline w/ a 107mm BB spindle (square tapered--ISIS, octalink and whatnot are other spindle-to-crank interfaces), a 110mm spindle will probably get you pretty close to a 42mm chainline