component / hdmi matrix switching

If I go with CQC to control my HAI & audio system (whether it's russound or nuvo), and then put a riva client on my ipad/iphone - is my experience close to what I can do with Sonos iphone client out of the box on the audio side?

While I haven't used Sonos, I 'd say that yes, your experience should be similar. JKish on CQC has created some really nice templates for music. He has added a bunch of custom macros and such that allows much better searching and viewing of such material. I'd recommend checking it out.

Obviously you would need to modify those templates to fit an iPad/iPhone size, but you can see what is possible.
look at AVAtrix
I am using this and have installed many and have had good luck with it. This is the company that does all the major sotres as well.

In anycase you can forget about hdmi matrix switching, there are some but what they don't rtell you because of the copy right people most hdmi sources can only output to one set anyhow, it is up the the manafacture to program this you can look at crestons site to check your componments and see how many they can output to. There is a new approved hdmi over gigabit network whch removes this limitation. Hardawer is not avaiable yet though and several sompanies are working on it.

Anyhow back to the AVAtrix the nice thing about that system is it uses 2 cat5e cables, much cheaper and easer to run than rgb and audio and IR. So the unit is pricey but it makes up for it in cable cost. Also you now have network cables run, hence my comment above HDMI over network. It is just a great one box solution they also have a big thread on av forum if you want to check it out.
Monoprice has a 4x2 for CHEAP. Discussion of it here:

It has a serial port on it also, which you can send commands to with the ELK M1 Gold.

HDMI is the standard now, but several large companies are on board with the new HDNet standard, which allows HD video over a single Cat-6 cable with RJ-45 connectors. No idea if it's ethernet compatible, but if it encapsulated the video into ethernet frames, you might be able to distribute with a standard ethernet switch. Although, you'd have little control over it unless you had a fairly high end switch. Assuming it DID work over ethernet, you could do your switching by modifying the VLAN's on each port. That would be sweet.

Edit: Looks like that one is gone. But they have this one, which is a 4x4: