Check out the Omni Hotel at Independence Park. It's in Old City but they charge about $25 - $35 a head (depending on your menu) for rehearsal dinners. The space is too small for a wedding reception in my opinion, but perfect for a rehearsal dinner or bridal shower of your size. Good Luck!
Re: Philly Reheresal Dinner
My friend had her RD at LaScala's in Old City. It is a big place and could fit 50. Not sure of the price, but the food was so yummy!