Welcome!

Your thinking is superb.

The new Logitech Touch is a wonderful product.

I the MMGs are an amazing buy. Stick with the floor standing version (MMG) as they have a much better frequency response. They are small enough you can easily move them out of the way when not seriously listeing.

They will need a bit of nice clean amplification.

I think you would like the MMGs over the MMGWs. As was pointed out you can always move them out of the way when you are not listening, they only weigh 20 pounds each. You would definitely need a subwoofer with the MMGWs which only go down to 100 Hz and also are not as dynamic as the MMG which extend up to 24kHz compared to the 16kHz of the MMGW and the MMGWs wall mounted don't provide the renowned backwave. Good amplification will help you enjoy the MMGs. I've been very happy with my MMGs driven by an Emotiva rack of the ERC-1 CD player, USP-1 preamplifier and a pair of UPA-1 monoblocks.

The Squeezebox is an elegant solution, but be sure to use lossless music files.

Count me as the third vote for the MMG's. Magnepan speakers sound best with some distance off of the wall so in addition to better bass response the MMG's will give you better sound because they allow more placement options.

Also to be noted, don't skimp on the amplification that runs the Maggies. They like good current delivery and your average receiver will not show you anywhere near all of the magic that they have to offer.

For affordable amplification think:

-Adcom
-NAD
-Rotel
-Arcam

If you consider used your options will open up. What is your budget from amplification?

I love my Squeezebox Duet, but I wouldn't want to be without a preamp. Have a good look at this before you decide:

http://wiki.slimdevices.com/index.php/Connect_To_PowerAmp

You really can't go too wrong with the Emotiva stuff for an affordable solution. The UPA-2 is worth a try; if you find it lacking you can always return it within 30-days for a full purchase price refund. I don't know if the "LEVEL" dial provides a full 0 dB to 32 dB gain or not. That might be something you could ask over at the Emotiva Lounge forum. It also might be a bit cumbersome to adjust volume levels with the small dial at the back of the amp. But, I'm sure its 185 watts per channel into 4 Ohms would be adequate for the MMGs in all but the largest of rooms. As was noted above ample power can bring out the best in Magnepans and my MMGs with 350 wpc do shine.

+2 on the Emotiva.

I'll just sit back and let Jackfish do all the work!

I'm liking your system already!

Quote:
If I get a preamp it'll probably be the USP-1 for the simplicity of having the amp and preamp be made by the same manufacturer (is this a good idea). With the Squeezebox Touch I will probably need a preamp at some point anyway since it only has two analog outputs, so there's no way to hook up a sub (unless I get a sub with a digital input?).

You could hook up a subwoofer with RCA Y-adapters on the Touch RCA outputs or perhaps with the subwoofer's speaker level inputs doubling up your loudspeakers and subwoofer from the amp's speaker terminals. The second alternative may result in funky impedance or interference though.

Quote:
However, without a preamp I would use the digital volume control on the touch instead of the level dial to control volume. The dial is just a potentiometer on the input, so it would allow me to adjust the input voltage so that the output voltage of the touch at 100% volume causes the amp to run at full power.

If the Touch has volume control capability then practically speaking you wouldn't need a preamp and could still use the Y-adapter solution for the subwoofer.

I really like the Emotiva stuff. The price/performance ratio is off the charts. All the pieces I got seemed to fit exactly with how I wanted to put a system together and that doesn't happen very often. The only thing I wish it provided is, while the ERC-1 CD player has a DAC which supports SACD, the unit was not built to play SACDs. However, for the few SACD-only discs I have I plug in my Oppo DV-970HD.

I'm building a very similar setup to the OP so I thought I'd just piggy back off his post...so here is the total noob question:

If you're looking at adding a preamp to help control the Squeezebox and power the sub, what does a preamp do (if anything) that say a 5.1 receiver that you already have does? I just bought a pair of B&W 683's and have two Emotiva UPA-1's on the way to power them. I'd like to add a Squeezebox to the mix and already have a receiver that can power my sub (Klipsch KSW-12). So, should I buy a preamp?

I'm just getting my feet wet here but I'd like to do things right the first time.

What receiver do you have?

Oh, sorry....Denon AVR-1610.

It's been my experience that the preamp section of most AV receivers leave a lot to be desired sound wise especially when used in two channel mode.
In other words stereo preamps usually do a better job on two channel music.

I would think that particular receiver would be a poor solution. The preamp outputs do not accommodate what you want to do. Think about a decent preamp to go with the power amp or a good integrated amplifier.