Re: which linux?
IIRC RedHat (Fedora Core) is the most common Linux among the customers of my workplace's shipping products for Linux. We also use Fedora core for our server product (VMware ESX Server)
Then SuSE, then Mandriva. You can expect to find help on the web from just about any Linux, but the most common Linuxes have the most prevalent posting of problems, and the most widespread posting of solutions.
I find SuSE wonderful for their support of ThinkPads, but for nForce desktops, I choose Redhat
I used to drive a Heisenberg, but whenever I'd glance at the speedometer, I'd get lost.