Do you have to mount the speakers up high and on the wall? Comparing the frequency response with the 170s, I think placing the HTM-200s at that height is going to force you to make some compromises. For one thing, you won't be able to get an ideal match with a subwoofer unless you set the crossover at about 100 Hz. Unfortunately, that will make it pretty easy to tell where the subwoofer is located. If you can mount them a couple of inches out from the wall, I think the 170s would work better...
Kurt C.
Radio Shack SPL meter, Avia HT setup disk
DIY Absorption panels
Athena AS-B1 fronts/surrounds
Athena AS-C1 center
SVS PB10 subwoofer
Panasonic RP-56 DVD/CD player
Yamaha RX-V650 receiver
Panasonic TH-42PHD8UK 42-inch plasma