I finally buyed this one:
http://cgi.ebay.es/Qtek-9100-i-mate-...QQcmdZViewItem
As you can see, it is very similar (but the same) that that you referred me previouly.
Im learning how to use it with a softphone (it has bundled wi-fi).
If I can, i think that it is better than our (yes, i buyed it also, for my wife in home) UTstarcom.
After that, I think that there are a system (i need to re read all in this forum to reach it again) that permit you (your phone) to select wifi if available, gsm mobile if not, im not remeber well it, maybe do you?