I'd go with a click castsequence.

The basic idea will be one button which calls several castsequences.
You'll likely want to use two of each rune type, and to get diseases up early.
And use a rune-free ability, in the fall through position.
Tweak the commas, so the fall through fires off around 1-2 times per rotation.

Stealthy has an Unholy click based, in the wiki: http://www.dual-boxing.com/wiki/inde...ro:Using_Click
I adapted it for my roommates blood DK, just changing a couple of spells.