What desktop-replacement laptop should I go for?

It’s time to retire the old tower I built up from parts. With a 5-year-old Intel Pentium processor and just 512 Megs of memory, it’s not even up to browsing today’s web. Throw a sophisticated formula at it and apply it to 10,000 rows of a complex Excel spreadsheet, and you can take a coffee break and come back to find it still thrashing.

I could just grab a new mother board, processor and some 1 gig memory modules and patch up the old tower system. I’ll do that sooner or later anyhow, as I have a new 1TB drive set for it and a spare Radeon HD 6850 graphics card with 1GB of GDDR5 memory on it.

But the old hard drive took a hit while moving this month, and won’t boot. Searching through my CDs, I no longer have the original Win-XP Complete CD. I have two upgrade CDs for XP, and so far have been unable to find my upgrade disk for Win 7 Enterprise Edition or any full edition to start upgrading a new drive from. So I am probably looking at buying an expensive complete edition of Win 7 Ultimate, going OEM, or switching it to Linux.

What’s more, today’s laptops are capable of far more than my old tower is. If I go with a desktop replacement laptop, I can plug in a keyboard, mouse and 24” monitor for work at home, and still have a laptop with a 1TB drive and all my current files on it when I have to travel. And it will come with the OS already installed at a fraction of what I would pay for a full copy (not an upgrade).

I do Web design and potentially video editing and graphics up to 3D design on it, but never really push a machine like gamers do. So I have no need of the fastest processor and many gigs of memory. Instead of paying for untapped horsepower, I’d rather keep the budget down around the $4 to $600 range and target something that has a good reputation for lasting.

What are some good quality, well supported desktop-replacement laptops to consider?