Hello, Am in the process of purchasing a Xbox 360 for my son during this holiday season and would like to have it modded so I can play games off of an external HD. Been reading a bit about modding and seems to be way over my head for the time being but will be reading more. However, the question that i have is which Xbox 360 should I purchase - 4GB or 320 GB? Is there any difference in modding the above 2 models or is it the same process for both? Or is there another xbox 360 model that I should purchase that would be easier to mod? Will it be possible to go on Xbox Live if xbox is modded or is the threat of ban always present on a modded unit? Thanks for your assistance.