What might not be a bad idea, and what we did for our wedding, was to have two "rehearsal" parties--one a small dinner for the immediate family and wedding party, then we went on to a cocktail/heavy hors d'oeuvre party at a separate location that all the guests were invited to. We had a lot of out of town guests and didn't want to leave them stranded without food on the night before the wedding.
This way you could do the actual rehearsal "dinner" at virtually any restaurant, and then the separate "welcome party"--as we called it at another venue that can more easily acommodate large groups of people such as a hotel. The caterer doing the wedding itself would be a good first choice for the "welcome party" and might even cut you a little bit of a deal since they're already doing one event for you.
It may or may not end up slightly more expensive to do it this way but I guarantee you'll have a better experience overall.