Hmm. After reading the following (a bit old, but still accurate?), I'm rethinking a bit.
http://www.prepaidgsm.net/forum/glob...view-t711.html
Maybe use Nokia as primary phone, on Wind, and use 3g HTC and PC on 3 ITA when doing data. Accept that we'll pay a few bucks for calls between the phones.
This way I avoid nuisance for calls when "on border between UMTS & GSM areas."
Thanks again for the site and other info!
Kevin