Well, then you're faced with the somewhat daunting task of installing from source, or, worse, creating your own RPMs. While I've made my own RPMs in RedHat, I've never touched a Raq, so I don't know.
Is vector linux the replacement for the linux that came on raqs from the factory?
And yes, source installs aren't quite as easy to back out, but they've always worked well in the past for me.
You'll need to build php by hand, but if the postgresql rpms include the headers, at least you won't have to rebuild postgresql by hand.