My son is now turning 7, and I live in Florida, as well. We have had the greatest success with just having the basic package party at Adventure Landing. They get to go on the go-carts (or laser tag), play mini golf, play video games, and eat pizza and soda...You can add the batting cage if you want too! They even include all the plates, napkins and plasticware!
Pump It Up and Big Air are huge hits, as well! :) And it ends up costing me the same amount as if I had thrown one myself (with food, decorations, plates/cups/napkins/plasticware) AND I do not have to clean up!
You could also go to a local park and decorate the cake with his favorite toys (last year we did Bakugan all over it--this year will be Beyblades) Most kids love to just run around and act like...well..kids! :)
We end up doing the park thing with our homeschool group, and then Adventure Landing with a set amount of kids...
We also have done Build-a-bear in the past and that can be as inexpensive as $10 a kid.
AND the great thing about having the party at one of these places...no-one goes home with "favors" that are just going to be thrown in the trash anyways...talk about wasted money!
Hope this helped some, or at least sparked some ideas