I just completed my 1st engine rebuild and I must say, buy the rings and other things like bearings after you have measured up the cylinders etc. I bought stock parts for my engine, put it back together too find I was burning oil and also had low oil pressure (undersized rings and bearings).
This part is just food for thought: Bearings are cheap (I dont knwo the prices over in the US but they were about $120AU for a set of rod and crank bearings), and because you will be pulling the pistons/rods out why not replace the bearings while your at it. If you decide to replace the crank bearings you will need to make sure your rear seal is put back together properly so it wont leak. But replacing the bearings means you will have to mic up the crank and do a plasti gauge test aswell to make sure you dont need oversized bearings.
You will need to hone the cylinders (makes a crossed pattern on them) for the new rings. But apart from gaskets (head gasket mainly) you can just replace the rings, hone the cylinders and put her back together.
Hope some of my ramblings has helped (even if its only a little bit).