Bearings come in different sizes and aren't all one size from the factory, so don't expect to see that from a rebuild kit. If you find one that does you can still plan on buying some more in different sizes... unless you're getting the crank reground.
There are some decent rebuild kits available on E-Bay that include main and crank bearings, oil pump, water pump, rings, gaskets, pistons, etc.. A few members on other forums have tried them without issue.
If you're going for a high horsepower build I'd probably just buy a full gasket kit and get everything else seperately. Don't cheap out on a high HP build.
EDIT: Here's the E-Bay seller's storefront:
http://stores.ebay.com/Mizumo-Auto-Parts