You will need a cassette and a chain. I don't think you need the tool until you are ready to remove the cassette, but for some reason I bought one when I first ordered the cassette for my wheels. You will need a chain tool for the chain. Buy a Park chain tool if you are going to do this.
The cassette is easy to do, but the chain installation could be a pain in the *****. Another option is to get a chain with a removable link like a Wipperman, but I always just bought Shimano. I follow the instructions that come with the chain, but I've done this a few times and kind of know what I'm doing at this point.
For the cassette, just get Shimano Ultegra. They are cheap enough and come in a variety of gear combos. Maybe 105 is a few dollars less, but not much. I think I have a mildly used Ultegra 9speed 12-25 sitting around. I'd have to look at the condition.
I think I've seen your moniker before on the audio boards, such as AudioAsylum? I used to go to those a lot, but lost interest a bit over the last 6 months.
And you say 'I moved to the city'. What city? There is only one of course, NYC.
Last edited by zacster; 09-27-08 at 09:28 PM.