To get any fleet ship with one fleet module, you need to own the C-Store Tier 5 version of that ship. IIRC, the Fleet Advanced Cruiser refit is 5 ship modules, so it's probably worth it. Alhtough I'm pretty sure you need a tier 5 shipyard, which we don't (yet!).
It's an impressive looking ship, and I've heard really good things about it. The Assault Cruiser is supposed to be good to--but between the two, I'd go with the Excelsior, for looks if anything.
From personal experience, I absolutely love my support cruiser retrofit. If you weren't able to get one from the three year anniversary, you can pick up the Fleet version, which I believe has the highest hull of Fed cruisers (43,450). It's one of the few ships where you can use both Eject Warp Plasma and Gravity Well, a wicked combination.