Arch is awesome, try it. When I used it, I made it crazy light with OpenBox as my WM.
And yes, CentOs is far better then Ubuntu Server, I tried Ubuntu Server and about 1/4 of the packages were either wired versions that had something broken or just broken. Everything is a bit older on CentOS, but for the extra stability, its worth it.
No need to try RedHat though, Cent Os is just Red Hat with out the support and branding.