ATC SCM7 vs. Proac Studio 110

Best you find a dealer that will provide a 100% cash refund after you listen in your home to each. That way you can use your cables etc. Since you have no local dealers you need to have the first choice shipped to you. If you are paying list, the dealer should pick up the shipping, but you need to pay for the return, if you are not happy. At least you will not get stuck for sales tax.

ATC will prefer more power and will have a more articulate tight and punchy
bass (no port) but it won't have as much bass extension as the Proac (reflex
ported). The ATC midrange and articulation will have the edge on Proac but the
Proac bass extension and efficiency will have the edge on the ATC. The Proac
will probably be a lot more fun (small speaker big sound) but the ATC will be
slightly more transparent and better mids. Take your pick.

I have the power to drive the ATC's. Your summary is excellent, I think, based upon reviews that I have read of each.

I'm leaning towards the ATC for the reasons that you describe as well as it being a sealed design and better suited to rear-wall installation.

I'm going to mount them on brackets attatched to a wall.