While that comment may have been true in decades past, manufacturers are pretty careful to make sure that their parts work with everything else out there. The benefits of standardized interfaces and codepaths...

Except for harddrives. In my experience, it seems like hdds don't like to play with other brands. IE, I tried to install a Maxtor hdd as a slave to a Western Digital, and couldn't get it to boot. But other than that, every thing should work dandy with your setup.