Well, your budget precludes the really top of the line stuff by people like Bare Knuckle and so on, but you can still vastly improve on the stock pickups, I'd say. Keep in mind that the guitar you're looking will shape the sound a bit as well, so to compare the pickups to how they might sound in other guitars can be a bit misleading.
For the bridge, I'm kinda partial to DiMarzio's Evolution pickup. It might be a little bright for some people, but there is plenty of power and detail for leads and heavy rhythm. Or you could go with their Breed bridge pickup for a warmer sound than the Evos and a fatter sound than the PAF Pro pickups. They're still plenty hot though.
For the neck I think the Air Norton is a good recommendation.
I'm not that fond of Seymour Duncan pickups myself. I haven't really liked their sound all that much in any guitar I've tried. I actually have owned a few myself and always wondered what the fuss was about. To me they didn't sound any better than a lot of stock pickups. All the other companies whose pickups I like that are in your price range don't make hard rock pickups; they're more geared towards the vintage sound.
Have fun with your new guitar! :)
