NEW YORK (Money magazine) - When it comes to laptops, there's a notorious trade-off between performance and mobility.

If it's lightweight and portable, it's probably also light on hard-drive capacity and processing power.

If it boasts a cinema-quality wide screen and enough power to support graphics-heavy games, it's probably too heavy to carry to the office every day.

We can't change that, but we can recommend two top-shelf $1,700 machines that give you one advantage without shortchanging you on the other: a Dell that's as light as a bunch of bananas but performs well, and a powerful HP that fits under your arm.

• Check out the "build it yourself" tool on manufacturers' Web sites to get an idea of your options, everything from a DVD burner to varying processor speeds and hard-drive sizes. Then draw up your desired system and shop different brands. Price differences for the same features may astound you.
• Don't ignore Wal-Mart, Best Buy and other stores that stock preconfigured systems. You can sometimes get an amazing deal on more or less your ideal system because the store doesn't want it collecting dust on a shelf.
• When you plan your PC budget, remember to consider the software you'll need. On occasion, computer makers bundle in a full version of the Microsoft Office suite, which on its own costs $400.
• If your desktop PC configuration includes a monitor and speakers, great -- just make sure they're what you really want. (Bad: 17-inch CRT monitor and house-brand speakers. Good: 17-inch flat-panel LCD monitor and Logitech speakers.) If they don't meet your needs, buy only the computer and use the leftover money to shop for speakers and a monitor elsewhere.

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