Get the xbox 360 premium. It has everything you will need. Had my system for 6 months and havent even used 1 gig yet. Also, I would buy from gamestop or electronic boutique. For $50, they replace the system for up to one year No Questions Asked. So if you decide to mod your system and you screw it up, you can get a new one. Compusa will try to figure out what is wrong with the system and if you tampered with it that voids the service plan.
Look at this site if you want to mod your system. http://www.xbox360-hacks.com/
They have hacks that allow you to play region free games(copied games).
Also you can download these games from bitsoup.org or thepiratebay.org.