I would actually recommend the Linksys WRT610N. The E3000 is really the 610N with a different skin. This was confirmed via a post on the DD-WRT forums. Not only is it the same router, but it's already supported by DD-WRT. The E3000 will likely be supported soon, as the only modification to existing firmware will be a change in the header. Here are links for you:
Linksys WRT610N
Dual Band Wireless N
4 Port Gigabit Ethernet
MIMO Technology
USB Support for external storage
DD-WRT Homepage
By the way, you may want to fill in your system specs via UserCP if you plan on asking more questions in the future. It will help users identify your problem and suggest a solution.