i'm looking for a microcontroller but don't know exactly where to look...?

well basically for this little project i'm doing, i expect to need some horse power, i was looking for about an 80MHz processor but no less then 64MHz and no less then 64MB of primary memory, and i've got a lot of code so i would need maybe 64MB or more to actually store the code (because i need wiggle room for upgrades. but this might not be a problem because i'm actually going to attempt to hook up a hard drive and could probably make use of that space as well and just have a core system on the EEPROM)

anyways, that being said, i'm having the hardest time finding one that powerful.

any suggestions?

also i have an Arduino Duemilanove, it doesn't measure up but if there was a way to add to it as far as processor and primary memory goes that would be an acceptable work around too.