Moving to new house-need advice on HT

We purchased a house in the country that the previous owner had installed in ceiling speakers for his surround system. I have been a 2 channel guy, but I want to integrate my current system into a 7.1 or 7.2 and have several questions, and I don't have a good AV dealer for 250 miles, so everything is off the internet, either new or used.

My current system is a Parasound P5 preamp, a Parasound A21 amp, Revel F12 speakers and a OPPO player. I love how this system sounds, and would like to build on it. I was thinking about heading the following direction, and would appreciate any advice to make this an easier project.

• Adding a Revel C12 center
• A theater processor, the Marantz's look good, must have HDMI, and I'll use the theater bypass on my P5
• A sub or two, I'm an old JL audio fan, but there is a lot said good on the web about SVS, Power Sound Audio, and HSU Research. Would probably buy sealed, I'm still a music fan, and a cheap sub sounds like a cheap sub
• A 5 channel amp, probably a used Adcom, Parasound, Rotel type.
• My main concern is inceiling speakers, I've seen Revel makes them, does it make a huge difference with timbre/voice matching the surrounds? I've heard Speakercraft are very nice for the money. Any suggestions would be greatly appreciated, I don't mind spending for quality, but looking for good valve.

Lots of questions, and I would appreciate any and all advice. My wife and kids are big on the theater idea, but I don't want to dump a ton in to this and they use it twice.