You are right Foam insulation is not a vapor barrier, but it is resistant to moisture. I suppose it would still be a good idea to put a vapor barrier on before the drywall. This problem only affects 8ft of my project. The rest of my walls will not be in contact with the exterior concrete walls.
That's sweet you have a pretty dry basement. In my part of the globe damp/wet basements are very common.
I've finished a few basements over the years and learned some tricks:
Avoid putting wood directly against concrete, capilary action will draw moisture out of the concrete right into the wood. If wood must go against concrete, add a barrier strip of felt or foam (like what is used on wood sills when installing to a concrete foundation). Treated wood is a plus.
Don't use batt type insulations, they will absorb moisture and ruin the R value of the batt. The foam types, as you selected, are an excellent choice as R value won't be affected if it gets wet.
And, contrary to popular belief, do not place a vapor barrier between your framing and drywall !! It will hold moisture in your framing and walls by sealing the airspace between the barrier and the concrete. In basement conditions you need to allow the walls to "breathe".
D