I am asume that you are a tac. I would get the following:
1. Valdore Heavy Warbird. This gives you the Shield Absorption Frequency Generator Module.
2. 4 Fleet Modules. I would recommend that you buy a Fleet Hafeh if you can get with a fleet with a tier 5 ship yard.
If not buy a Dhelan and get 1 fleet module. You can grind STFs all day long with these escorts. Or you might want to hold the zen and use it for Dilithium because you are going to need it for XII weapons, and sets when you get up the rep system.