Like Alex says, You can be almost as fast as a Magwell, with rock-n-lock and practice. Carolina Shooters does sell a rock-n-lock guide, which I've heard from multiple sources, is awesome at speeding up the rock'n'lock style.
I have a Gen1 AGP and Gen2 Surefire magwell from Jack, and while the surefire version is better, i prefer the AGP mags, so I switched back. I'm actually going to sell my Gen2 Surefire magwell and 3 moded and functional Clear Surefire 12rd mags. You can see it here in the white:
I couldn't wait for him to anodize them so I got one white
Anyway, I recommend a MINIMUM of 3 mags and something like 4-5 is optimal. I've yet to shoot a stage with more than 30rds.
And the drums, MDarms 20rd drum is the best out there AND they're running $100 now. You cannot use a magwell but you can use the mag-guide with the drums.