I'm sure that they won't take a housing voucher because most landlords believe that all tenants that receive assistance will destroy their property because some people do, but everyone shouldn't be judged based on the actions of past experiences that have nothing to do with you.
I have lived in Roxbrough most of my life and the area is in demand and landlords don't have to go through the process of becoming a PHA landlord and most don't want to have to keep their property up to housing standards have to deal with the yearly inspections by PHA.
In Roxbrough/ Manayunk they can demand high rent and get it from students looking to live near Manayunk and the yuppies that are looking for a nice area to live in, but don't give up..
Try GoSection8.com and you should be able to find housing just be entering your zip code.
Trulia also listings for..Incom Restricted Rentals and you can try some on the apt complexes in Germantown, City Ave, or try using a realtor that to hep you with your search.. But Gosection8 is your best bet, at least you know that they will accept your voucher. .