Breast forms are a widely used solution for genetic males who want to have a feminine look and the Breast Form Store has a great selection of quality products. I see questions from time to time about those rubber vagina panties, but I've never heard from a satisfied pur->-bleeped-<-. They certainly don't look realistic to me and I'm sure they're quite uncomfortable. They're expensive, too, and some are made of latex which may last about as long as a rubber band. I think for visualization purposes you'd be better off doing a bit judicious tucking and taping.
If you work on your photo editor skills a bit it's really not hard to get a pretty good idea a different appearance that way. Use your camera's remote or self timer to snap a well lit frontal pose against a plain background. The proliferation on the web of images of the female anatomy make it easy to find something that matches most any photo you have. I did that years ago. I wouldn't rate myself "10", but it was not a bad look for me.