If you only knew how well I know the front end of an A4...
I have the job coming up this spring - I will definitely report (honestly) on how long it takes me.

If I want to do it myself, what tools do I need, and what's the best place to order the parts from? and most importantly, is it a easy or hard task?

Main tools youll need that arent in some peoples collection are torx bits, hex wrenches and a couple universal joint joint ratchet adapters (i think thats what their called)... Its not hard, just time consuming. Make sure you read over a DIY article a few times before hand and have it with you during the job. A friend always helps.. I got mine done with my uncle in about 6 hours (including snub), cost me about $350 inc. shipping for the kit. There are write ups on it everywhere and most tell you what tools you need. Being prepared is half the work.
i got mine from ecstuning.com but i hear e car toys . com and even ebay has kits that are competetively priced.
But thats just all for the 1.8t

Holy crap.. Audiforums astix's "e car toys" out if you type it the right way! Hmmm.

Guys this 3.0 T-Belt setup is wayyyyyy different than a 1.8 or 2.8

You have to remove both valve covers to lock the cams theres no bar that goes on the front anymore (kinda stupid if you ask me)

It takes about 2 hrs more than the others

But I myself havent done one yet this is just info from what ive seen