Linear / National / Motorola make good buck and or boost converters.

Everyone is pitching components for laptops and PDAs though. That means you have a lot of component screening to do online.

An important first question:

(1) How much current do you require on the outputs

and while you're at it:

(2) What is available at the inputs.

Don't get sloppy on DC/DC converters and ignore currents - it will bite you.

-duh