Type the message, then tap the little camera icon to the left of the text entry box. That brings up the option to take a new picture to add to the text, or to use one from your camera roll.
Just started listening to the Aragon DAC that arrived in the mail today. Feeding it HDCDs from the iMac via Toslink right now to very pleasing effect. As a 19" rack unit, it's not really a viable desktop piece, but here it is crammed in and adding yet another color to my LED rainbow.
Sorry, got no relevant experience to share. Just thought I'd mention that, in that sort of speaker vein, you could also look at Tekton Design for some other options.