How about some mature comments for this guy, instead indulging teenage fantasies all the time?
I'm no expert, but do you have any friends that have had the op? Im guessing not if you're asking here for some advice? Try this link? It shows you the two main types, saline and silicone, and some pros and cons of such an operation.
http://en.wikipedia.org/wiki/Breast_implant
It should also be noted, that if she goes ahead and has an op, theres a good chance your wife may have to have additional ones in the future...