You sould try to just sign up as a net passport and register your gamil thats wat i did and everything is working fine but the only problum you will get is that msn wont check you gmail you should just download the gmail check from here:
http://toolbar.google.com/gmail-helper
but patchou is going to work out how messanger plus will check for gmail but it is not working right now so you will have to use the gmail checker