Chaos HQ-500pts

Hiya, its jacob here just wondering if anybody could help me out here on my 500pt chaos space marine HQ choice.

My Army List Goes Like So.

HQ-?

Troops-7 plague marines
5 Bloters
1 Flamer
1 Melta

Troops-10 Chaos Space Marines
8 Bloters
2 Missile launchers

The thing is i'll be going up against a lot of Eldar, Space Marines & orks.
The Missiles will fire krak at the Space Marines (is frag better?) & the wraithlord (yes he has one in a 500pts list. i made the list for him :nono. And Frag for Orks and Eldar Guardians. The Plague Marines are more of my front line force, with T5 and all those bolters and assault weapons. For HQ i have a couple of variables although i will welcome anything. I have 60 NZ dollars to buy my HQ. In case you do not know what 60$ is equavilent to... its enough to buy a daemon prince.

HQ SUGGESTIONS-145 points:
Daemon Prince-MoN, Nurgle's Rot.
Daemon Prince-Wings, Doombolt/any other psychic power
Chaos Lord-MoK, Juggernaut, Power Weapon, Bolt Pistol.

as you can see it doesn't have to be Nurgle-perhaps Khornate Daemon Prince with wings?

Thanks Guys!