Orpingtons are great birds! My last remaining original hen is a Buff Orp, and she's a delight.
I think you are making the right decision about holding off on the Rhode Island Reds for now. I can't really tell how large the coop is, but it looks like five full-sized birds would be pretty crowded in it.
Still, a free coop is a lovely gesture by your neighbor, and I hate to waste anything free.
Good luck with those little ones, and welcome to BYC!