I use an input switcher in between my amps and my two preamps, one is a dedicated 2 channel and the other a HT 7.1 processor. I have my HDMI running directly to my TV and my digital audio running directly to the the processor. I just switch off my other surround amps when I'm listening to music. Dr. P at Mapletree Audio
http://hollowstate.netfirms.com/otherproducts.htm will make a line router/switcher to your specs.
My processor is a B&K Ref 30 which is great for TV, movies & gaming. You can pick them up for next to nothing since the company sold out to ATI. Rotel is another good buy, both are all over fleabay & audiogon for cheap. Outlaw, Adcom, Emotiva, and even older Sunfire stuff can be had for cheap. They're all pretty much programmable as far as digital/analog input & output routing.