I would also consult an accountant or an attorney. Also know that the types of financing would vary as well if you purchase a property in a LLC or S-corp... in most cases, you would need to a commerical loan and your rate could be higher. So if you are just doing one rental property doing it in your name is not that uncommon.
Perhaps a mortgage pro can chime in on the differences in terms of financing ? Either way, that is another item to consider.
Where are in Philly are you looking for the investment property ? For some good options, check out http://www.phillyinvestorhub.com .
I have an LLC in place for the purpose of doing business and it is what suites my needs. I wouls suggest you speak with your accountant or attorney to figure what would best suite you. If you need, we have have those professionals available for you.
PeterB. Lavelle, GRI