I think any of the custom winders would be a good choice but are usually pretty expensive by anyone's standards. I can personally recommend Manlius pickups.
Custom Handwound Guitar Pickups from Manlius Guitar Pickups They are outstanding.
This guy:
HighOrderPickups.com Will custom wind some for you at a much lower price. He's not as high on customer service as others I've corresponded with but he seems willing to put a good product in your guitar.
There are always the DiMarzio's and the Duncans of the world. I doubt you can go too wrong with those. Guitar Center online or Musicians Friend would be a good source.
Here's a site:
Humbuckers
Don't know anything about them but they have a decent selection.
If you're on a budget I can't recommend GFS pickups enough:
Home They are, IMO, worthy of competition in the $60-$70 range but sell for half that. depending on your personal preferences I can whole heartedly recommend their Fat PAF, Vintage '59 or the Crunchy PAF as improvements over the stock Epi pickups.
And I have to point out that I'm selling a set of Gibson pickups from my Epiphone Elitist just in case you're interested:
For Sale: Elitist Pickups
Good luck and have fun.