Some of you have made beats with programs like reason I'm sure, where have you found your different kits for things like dubstep?

I would recommend the Vengeance Club Sounds and Deadmau5 Xfer Sample CD sample packs

These together are a few gigs of stuff so you should be able to find a sound you're looking for or at least something close which you can customize

Downloading vsts and create your own dubstep sounds