If you're looking for a good deal and great rental interest - think about Naval Square. I get 10-12 inquiries every week about rentals there. I've had clients rent there sight unseen! Free parking, pool, new gym and free shuttle to UP and CC. The Phoenix at 1600 Arch is another idea - the auction results give excellent guidance for more units to be offered soon.
Hit me up at 215 266 7227 if you want to know more or discuss other options.
If I am not mistaken, 23 condo is offering some good financing packages right now. They have sold a few units recently and Turchi Properties does offer some nice properties (they have a few buildings for rent in center city).
Sales manager's name is Bob and should be able to help you and give you info on occupancy rates as well as what financing packages they offer.
Long and Foster Real Estate Inc.