Get a 5 gallon tank with a betta. Then you can add a couple of Otos down the road (great tank mates and they can be fun little buggers). Filtering a 2 gallon can cause too much current... and trying to lower the current to an acceptable level while keeping filter efficiency can be a bit more difficult. Plus, the more swimming room, the more enjoyment your betta will have. Happy betta = more enjoyment for you when viewing the tank.
If you can, try to do a fishless cycle on the tank or add some mature filter meadia. Search "cycling a tank" in google for more info if you are not familiar with the process. There are also some very helpful topics on this forum (i just don't have them bookmarked on this computer).
You can also add white cloud minnows, corys, and a select few of other fish. Search this forum for "betta tank mates". Keep in mind that some of the advice on this forum is ill-advised..... so do your research.
If you have any questions as to tank mates, post in this section and we will gladly help you.
Work on making your new betta jump, follow fingers, and even petting him. Your fiancee will be hooked on bettas in no time.
edit: lol, there are some other cool fish options.... but you are in the betta section after all.......