Having done this once myself and still regretting it, I wouldn't advise adding an anemone this soon. About two and a half years ago, I had a 75 that had been set up for about two months, parameters good, blah blah blah, and saw a CB maroon clownfish/cloned BTA pair at my favorite LFS. I succumbed to temptation and brought them home two days later. The anemone lasted less than a month, in spite of my best efforts and the fact that it was in a decent-sized aquarium with good flow, adequate lighting, no predators, and an appropriately sized clownfish. The tank was just too new.
On the other hand, my current setup has been running for 18 months. I bought another anemone, a locally cloned RBTA (rose bubble-tip anemone) at a reefing event two weeks ago, and added it to my tank. So far this anemone has been flourishing, and I'm very glad I waited. It can be frustrating to have to exercise patience, but it definitely is rewarded, especially in this hobby.
Anemones are fascinating, no question about it, but they can also be a PITA. I can tell you that I do a lot more tank maintenance and water monitoring than I ever did before--about 30 minutes a day. I worry about going out of town, because there are no experienced reefkeepers in town to do tank maintenance for me, and wonderful as my pet sitter is, I don't want to charge her with the responsibility of caring for the anemone. Lighting, flow, water parameters--all have to be just right. Anemones are definitely not for the new reefkeeper. If I were in your position (and I was, three years ago

) would start out keeping your clowns with some easy-to-keep soft corals; they may even take to one as a host. That way you can enjoy your tank and build some experience without the angst of worrying over an anemone. There's always time to get one later.