[Xabre]

Here is my initial 1000 points:

Chaos Lord w/ Plasma Pistol, Power Sword, Sigil of Corruption, Gift of Mutation = 130
(I know the plasma pistol is unnecessary, but against battle suits.. it could be useful)

The power weapon will be far more useful. Unless you just have the points to spare, drop the plasma pistol.

10 Chaos Space marines w/ Power fist, 2 Plasma guns, CCWs (x9), Veterans of the Long War (x10), Rhino with Havoc Launcher = 280

9 Chaos Space Marines w/ Power fist, 1 Meltagun, CCWs (x8), VotLW (x9), Rhino with Havoc Launcher = 244

Probably don't need VotLW unless you've got the spare points for it. Especially not against Necrons and Tau.

Helbrute w/ Reaper Autocannon, Power Scourge = 120

This brings me to 774. Here is the two options I now have to round out to 1000 points:

2 x Helbrute w/ Reaper Autocannon, Power Scourge = 240 (2x120)

Stop there.

With three Helbrutes you can use the Mayhem pack formation from the Helbrute book. You get to deep strike all three of them together (something Helbrutes usually don't get to do) and let them cause all sorts of havoc. Plus they roll Crazed every turn even if they haven't been shot. I might go with a different load, however, possibly Melta/Fist/Heavy Flamer so that no matter what's around them they can make a mess of things.

 

[Xabre]

Meh. That's up to, I suppose. If you have the points, wouldn't hurt?