I've got a warlock on my PvE team.
Pally, 3x Elemental, 1x Warlock.

But I have the Boomkin on the mixed team.
Mage, Priest, Druid, Shaman, Shaman.
Everyone is caster spec, although the druid is dual spec (Feral) and the shammy on the warlocks account is dual spec (Resto), as she was the healer when the first team broke into heroics.
This team is all caster dps, since its faster for dailies then with a tank/healer.. and they can do all the dailies in my route.

I'd recommend a DK tank (hard to recommend over a Pally) or a Warlock over a Boomkin, for the 13% spell power.
But if you have the Boomkin already and don't want the other two options.
Either you manage the Eclipse proc, approximate the proc, or ignore the proc.