If you are thinking Kenne Bell down the road, then pick your cam based on that. The TFS is a great cam from what I hear, but I think it is primarily designed as a NA cam for use with Twisted Wedge heads. So just make sure you do plenty of research on cams for the KB.
BTW, if you do the cam, then the heads, you will probably want to do your intake next, cause that will be your bottle neck. Then you will want to do you TB, injectors, MAF, fuel pump/FPR, headers. All those parts build off the others.
So maybe you want to think about just starting with the KB, and call it good?