In fact, get all the attachements. You definitely want that thing that goes up her asshole, trust me.
http://www.amazon.ca/dp/B00K0NGJKW/ref=twister_B00INLDN2K
I can't be the only person that snickered when I read that..
I agree with Prometheus though, buy a quality product over the generic pos that will need replaced more quickly. My woman is getting ready to attend a party here in two weeks for one of her associates birthday, and its one of these things where they bring in a hostess to sell them sex products.. I was all game for it. If your looking for dual purpose, buy her a vibrating butt-plug that doesn't look too conspicuous.. that way she can use it as a vibrator, or you can pop it in her ass and fuck her randy.. lol..
Also, if you can no longer get her off with your tongue... you might nee dot change up your moves or strategy. I've never had any real problem getting the desired effect when using my tongue.. remember to build, not just go in tongue thrashing.. unless shes drunk and already soaked.. build into it.. use your breathe.. use the tip of the tongue.. even dip that tongue just slightly lower (you know what I mean).. fingers are to be utilized.. I've got pretty long arms, so I can essentially semi-choke my lady (not top hard, the way she likes it) and use my tongue at the same time.. generally that's more than she can handle anyways.. Also slow rythmic pace with building intensity, cant go wrong.. and when it doubt about being able to build the pace, stop and rub your fingers up and down the slit really fast till she squirts.. you know, just the usual stuff.