Low-content: Newegg & Lenovo

I'm a Lenovo user, myself, but I've had a penchant for Newegg and the whole build-a-computer-yourself scene.

I figure I could get a decent graphics card and one of the ridiculous i7 processors, chaining in some 6GB triple-channel DDR3 for a super-fast computer.

Given my current laptop's meager 2GB dual-channel, Intel Core 2 P8700(2.53GHz * 2 CPUs), and ATI Mobility Radeon HD 3400, it's not that hard to get much better.

I'm also not a very experienced PC-builder, but my requirements in a computer are very simple:

As little space consumed as possible. The less space it takes up, the better. I really like the booksize machines that Newegg offers, except for the lack of muscle that they accordingly possess.

I've been eying the newer Lenovo IdeaCentre machines (as well as other all-in-one touchscreen sorts of computers), and the interface continues to grow on me.

What sort of computer would be ideal? Would it be better to build my own? I haven't seen any well-done touch interfaces with large amounts of screen real-estate.

Your thoughts, please.