I've used a couple of On One hubs (I presume they're ambrosio identikit copies). You're probably better off just getting the LBS to cold-set the rear end down to 120mm as you'll have far more choice.
Check http://www.on-one-shop.co.uk/acatalog/Rear.html £15 - bargain. I've had one going for about 2 years now, good sealed bearings (although I do have some 'better' ones for when they eventually need replacing), and finish is very good quality with no sign of pitting etc. through two winters.
BTW, are you intending to do this on the cheap? If so I have some bits and bobs in the parts box that'll probably come in useful for you - just drop me a PM.
Check http://www.on-one-shop.co.uk/acatalog/Rear.html £15 - bargain. I've had one going for about 2 years now, good sealed bearings (although I do have some 'better' ones for when they eventually need replacing), and finish is very good quality with no sign of pitting etc. through two winters.
BTW, are you intending to do this on the cheap? If so I have some bits and bobs in the parts box that'll probably come in useful for you - just drop me a PM.