Nurgle!!!!!!!!!

Plaguebearer units really don't need to be so big. Units of 7 are plenty resilient to hold or contest objectives, often for 3 turns while in combat. The Beasts you'd be better off with two units (in my experience) and using the extra points to buy a Nurgle Daemon Prince with Gaze for increasing your count. Oh, and drop the Soul Grinders for this list and make them Nurgle Daemon Princes.

With the points you save with the Plaguebearers, you need Nurglings. They benefit immensely from the tally and will make terminators cry when your tally hits 20.

Not a big fan of Kugath myself as a regular GUO is half the points unkitted out.

These are my experiences with the Epi list. It's a blast to play and if you deepstrike your units well MEQ armies will struggle to break even.

Good luck!

Also keep in mind that your DP's are going to do the majority of tally making. If your opponent wastes time sending troops to chase down Epidemius, you're going to do fine. However, if he realizes early on that the tally is increasing solely on the backs of the DP's, things get a lot harder.

For my Daemon Princes, I outfitted them with Mark, Wings, Gaze, and Iron Hide, and Cloud of Flies. It's an expensive set of upgrades, but allows for the long range shooting that hits on 2's and wounds on 3's, and doesn't allow regular Marines an armor save.

Again, good luck! Lets us know how your games go.