Yeah, I used the Xt arms for a while, they are a bit thinner than avid arms, this means you can set up the brake with the arms closer and pointing vertically. I found the fatter avids tended to stick out more and were easier to catch and lost some power. If the Xt arms are too much, the LX ones are just as good. Don't bother with avid ultimates. I don't think sealed bearings are good for the the application. There's too much crushing force on them and they go rough. This can intefeer with the pads hitting the rim evenly, As for pads, DON"T bother with vee daptors. they are fat (see above with brake arms) and allow the pad to wobble like a magura....One of the main advantages with a vee is that the pads a re locked solidly into place, this gives they even and a long wear life and increases hold. I would recommend some rockpad cnc vee pads as the backings have the strongest threaded post (although the TNN vee pads maaay be out soonish in a vee version). Untill the TNN vee pads come out, the best pads BY FAR were my Joypad material ones. Fatmike now sells them as Phatpads, so get a pair of re-fills. I would also recommend a booster, even if the brake is stiff without one, a booster will double the amount of hold the brake has. Oh, and get some decent cable! Its a bit of a hassle, but go to your local bike shop and get them to order in a 15m roll of their oversized shimano gear cable. Its basicly the same as linear slick cables, but better and you get 15 meters which lasts ages! DEFFO worth getting. I also got a bulk box of inners (100 cables) 4 years ago, its still got plenty left now, I would recommend getting a box too!