If you are really going all out for your kids next party, you could consider buying a bounce house! They are surprisingly not that expensive (starting prices). You can buy one for $299 which is better than renting and then you can use it again!
My daughter would like this one. It's $359.99.
You can go here to Play House Bouncers to see all the different kinds of bounce houses and water slides that are available.
Check them out on Facebook here for specials and giveaways.