That is really interesting and makes perfect sense - they immitate language in so many ways that the way they cry seems like a natural progression of that.
And totally butting in on the splash suit but I rememebred a catalogue we used to get in the UK that sold them so I grabbed the link in case either of you were interested. They're pretty cheap but I think probably reliable - this store/site was really good the few times we ordered from them.
http://www.thebabycatalogue.com/Splash-Suit-Red/productinfo/BW110/
also, if either of you have the ability to get stuff sent from the US Land's End has really nice winter stuff. Don't know that you'll need proper snow suit type stuff, though.