Hi C.,
I would advise against renting a pump. The expense will get to be quite high and then you could have bought one for much less than what you end up renting one for. We rented one for a few weeks after the birth of my daughter because she was born early and we were unprepared. We delivered at Plano Presbyterian and they use the Medela brand pumps - they are GREAT!! I ended up buying a Pump in Style Medela brand pump from A Mother's Gift inside the hospital. It was a great pump, fairly quiet, and comfortable to use. You'll probably spend close to between $200 and $300 for a good pump, so be aware of that, they're not cheap. Once you are finished with using the pump, you can always sell it on ebay. There are always people in the market to find a good used pump, even moms on here.
Good luck with your delivery, it's just around the corner!!! My c-section is scheduled for October 1st, so I'm right behind you!! I see you're in Plano, what hospital are you delivering at?
-Char