I really the the NuVo for its simplicity and price points. Russound is nice as well.
If your home is pre-wired for the Niles keypads then it is unlikely that you have speaker wire in the boxes behind the keypads. you probably have CAT-5 between keypads and the central breakout point where the Niles receiver is located. the speaker wires are likely located between the breakout location and the speakers and therefore completely routed away from the keypad locations.
The impedance matching speaker selector box should not be used in conjunction with the Niles receiver. I assume this is leftover from some other aplication?
The programing of the keypad macros can be quite involved and takes much trial and error. If programed properly the keypads should be fairly intuitive. If you would like I can email you a diagram (Solo keypad)that I give to customers explaining how to use the keypads of a specific installation. This could give you some ideas on simplification of keypad layout. It may be worth the money to pay a local installer to tweak the equipment you already have rather than replacing it.
The Xantech IR repeater kits are very good and reliable.