A park BBQ would be awesome if I lived in a town and we had a park, but we're very rural.
I could do a play centre thing, but honestly I'm not prepared to spend hundreds of dollars. July is generally freezing here aswell, so I have to have an indoor backup plan.

What do you think of only inviting boys? I HATE the idea personally(because I don't like to divide the genders and have DS thinking there is a massive difference between boys and girls at his age), but there are only 5 boys in the class. Obviously DD will be there (but she is pretty tom boyish anyway and will fit right in).
Argh. I'm most likely totally over analysing everything, but I would hate for anyone to feel badly (and I want my son to have an amazing party... we don't have parties for the kids every year).