Boy, that is a hard call to make. Thye ought to be rebuilds, but it's hard to say where they were rebuilt and so hard to say what can be good/bad/indifferent about them. Let's just hope any seats are set in better than the last set! I can see going either way here: run with them and keep your fingers crossed or have then checked over..
BTW as for cam selection, do you want to run with the valve springs that will come on these heads? Which are very likely just simple stockers. This seems like a project to build just a solid, reliable basic engine with part off of the shelf.