Agree with Bomber...don't even think about renting from Alamo unless you are configured for a Quicksilver rental!
As for rental car types, I personally like Intrepids. They are pretty roomy - I certainly prefer them over a Buick Century.
Your best plan would probably be to join FastLane if you haven't already and go that route.
FF bonuses and other promotions can be found at the car rental website...or here on FlyerTalk under the appropriate boards.