There are many sellers who have decided to rent so there are rentals every where. You may want to decide on a county first. If you work with an agent be honest and tell them you are looking in several counties. They may decide to refer you to an agent in another county if they do not service the county.
There are quite a few townhouses and homes for rent in Lower Bucks County, as well as quite a few apartment complexes. There is also a very wide range of prices in these rentals, depending on the area and the amenities. If you email what you are looking for or need, I will research it and email you back some possibilities. Homesfromtoni@yahoo.com