Well, first thing's first. The Atom really sucks for portability on an electricity budget. SSD is kinda pointless for a portable device, honestly. Just solder some chips on the board. Cheaper and easier.

The problem with putting all that junk into the docking station is gonna be bandwidth. There really isn't enough of it over a docking connector to make it work with the RAM, second CPU and video card.

Honestly, what you're really after is a decently powered tablet device that can hook up to a screen and keyboard without issue.

Soooo, N900 + DVI.