The best thing is to go togun shop that has a range and try out some. There are lots of comapnies that make excellent guns.
What part of PA are you from?
My carry weapon is either a Ruger P345 or a Taurus PT745 Millinium Pro, both at .45acp.
Probably be best to begin your search for a 9mm, lots of comapnies make excellent ones, hence the gun shop. You want to find something that feels good in your hand. I think something with a 4" barrel would be best, a little harder to conceal while carrying, but shoots easy as well.
For safety a Taurus 24/7 in 9mm can't be beat, comes with a keyed slide lock that prevents the slide from being operated, with three kids here at home that was a plus for me.
I don't know if you have friends who shoot, they could help as well, maybe check out the PA gun owners site as well www.pafoa.org/forum/ It's a excellent site