Slackware recognizes a ton of stuff. You only have to build something if support isn't in one of the kernels included on the install CDs. I personally have Slackware running on 5 boxen, and the only piece of hardware it doesn't detect and support is a Toshiba software modem and a Microtek ScanMaker 4850. No other Linux distribution is going to recognize them, either, because they aren't supported in a Linux kernel yet.
Which Promise RAID controller do you have, which hard drive, and which kernel are you choosing? It will have to have support for that controller in order to "see" your drive(s).
Check
Linux on Laptops and
TuxMobil to see if someone posted any information about your particular laptop.
Also check the
Linux Hardware Compatability List here at LQ.
When booting from the Slackware CD1, you can hit F2 and then F3 to read the choices of kernels to install. You might need to use ataraid.i or raid.i