Most agencies, as well as even the hospital, require that the nurse's legal residence be at least 75 miles away to get the housing deduction. The biggest perk with travel is the housing allowance.
You can also get very good per diem contracts in your local area.
I wouldn't worry about whcih specialty to pick, but rather which one do you love the most. The other thing with agency or travel nursing is to be able to be very flexible.
Good luck.........................