You won't need to do rods unless one or more of them are damaged from the spun bearing. I know the last time I lost the bottom end like that, the rod bearing that went ended up welded to the rod.
But if the rods are in good shape, they're plenty stout unless you're looking at crazy boost, and then you should also be looking at sleeving the cylinders and other crazy build up stuff.
Forged pistons is a good idea IMO, if you're going through the cost already of pulling the motor apart. Sure you're looking at an extra $500 give or take, but that's the biggest weak link in the stock bottom-end.
Like Dean said, a gasket rebuild kit is going to include all the gaskets/seals you might need. Again, if the motor's apart, might as well replace all that stuff so the motor is good-as-new when it's done. I believe there are kits out there with the water pump, gaskets, and timing idlers as well.
Headstuds aren't really necessary unless you're planning on running a bunch of boost. But they are relatively cheap insurance for the head gaskets, as you probably should be replacing the stock head bolts if you're not doing studs. Just make sure you follow the right torquing procedure for the studs, since it's usually different than the stock bolts.
Also speaking of head gaskets, new OEM gaskets should be fine... no need to spring for Cometics or anything.