Agree with skooter, in addition you will want a good mechanical aptitude, all the right tools and test equipment, plenty of time, a shop manual that you have read through and understood. I would also suggest a contingency plan, a mechanic or other person willing to take over if you get half way through and decide its out of your league. Better to arrange this prior to starting just in case. While the heads are off you should check for warping too, best done on a sheet of glass with a feeler gauge and repaired on the same with some wet and dry on the glass and a figure 8 motion on the head while held flat on top and checking often. youll want a torque wrench suitable for aluminium also and an air compressor and parts washer and large clean area to work in. I'm not trying to talk you out of it, just trying to let you know what you're in for. If you are only trying to save money and you don't have most of what you need then the additional cost plus the uncertainty factor may make it unviable. Also, you want to be certain that it's only the head gasket that is the problem you need to fix and the Pistons, rings, bore, etc are all sound otherwise it may be all for nothing (except a new experience)! If you knew a mechanic of any description that was willing to come over for a beer every now and then and mentor you a little along the way then that would also be nice. Be super careful with any bolts that don't crack open and remove easily, snapping a bolt in the hole is not difficult and will open you up to a whole new world of expensive, time consuming, frustrating pain.