Cabinetman gave some good advice. I donít normally use a T&G, though I wouldnít completely discount it. Edge to edge joints that are done properly are stronger than the wood itself, so the T&G doesnít add strength. The T&G can help with alignment though. It would depend on how bowed the wood is to begin with, and how easily you can line up the boards. I typically buy rough stock, do an initial surfacing then glue them together a little fat. Then I use a plane or belt sander to even out any slight discrepancies. Donít count on machines to get out big discrepancies though - get it as perfect as possible when you glue and clamp.
For anything except a huge table or an odd design, a final thickness of ĺ inch should be adequate for a tabletop. Ripping the boards into thinner strips should help you avoid a wavy top, but make sure you align the grain properly when you glue up the boards.
If you are planning on doing much woodworking, a jack or jointer plane to flatten boards is a good investment. I agree that plywood is an option, but you can sand through the thin face veneer easily.