oUF Phanx Runebar
 

Is it possible to disable the Blizzard Runebar?

Yes; install an addon that replaces it with something else. oUF Phanx does not include a rune bar (yet) so it would not make sense to hide it. Any addon that actually provides a custom rune bar should hide the default one.

Before i had perl but it was too much and oUF is nice with oUF_Phanx.
I Have for Runes only http://www.curse.com/addons/wow/magicrunes :(

Try browsing the Death Knight addon category on this site. There are dozens of rune addons. I'm sure you can find one you like, with an option to hide the default rune frame.

Okay, I've finally added runes to oUF_Phanx. They seemed to work fine in the 30 seconds I spent testing on a fresh level 55 death knight, but let me know (preferrably via a bug ticket) if you find any issues.