If you're looking for something with a longer barrel, then the Ruger MK series is probably your best bet. They're a little bit above your budget if you're looking to buy brand new, but used specimens should be much cheaper. Used is just fine as these guns are built like tanks.
Mags are usually about $20 a pop depending on where you order them from. I would stick with the factory mags and not cheap out with the 3rd party ones.