If you are up for making one, I recommend the Key Lime Pie recipe from The Best Recipe, put out by the Cook's Illustrated people. I have half of one chilling in my refrigerator-- the rest was devoured at dinnertime. The recipe is very easy, especially if you buy a pre-made crust. The only remotely challenging things are zesting the limes and separating four egg yolks. Make one-- it will likely impress your wife, and cost a lot less ($6 a slice? I could make 2 pies for that).
On the subject of lime juice, the cookbook authors say "We'd love to be able to say that Key Lime Juice made all the difference in the world, but it didn't. To our tasters, it tasted pretty much the same as the juice of supermarket limes." I tried Key limes once, but they were not worth the annoyance-- I (and my tasting panel) agree with the CI folks that supermarket limes are fine.
Cheers, Jen