What are the four guitars you have so far? What you choose should really depend on what you have already. You don't want something that is going to feel and sound exactly like your other other axes.
With that said, I am a BIG fan of Ernie Ball Music Man. However, since that is out of your price range, why not take a look at OLP? I've heard they're very solid axes, and they just came out with a John Petrucci Model which is in the $400 range if I'm not mistaken. 24 frets and a trem are among its chief features. If you want to know any more about ErnieBall or OLP, feel free to PM me with any questions.
www.olpguitars.com