You have my best wishes.
www.bluenile.com is good but you may find a better deal haggling with these people:
http://www.ashford.com/home/index.asp
"My name is RedskinRat and I'm a shopaholic".
Oh, and anything over 1.5 carats can look ostentatious, anything under .75 can look cheap (depending on the cut and clarity etc). If she has her own loupe you're in trouble.