in need of some advice.

[spaceman91]

I am going to try and do my slaanesh army. everything will have his mark/icon. I haven't got my codex yet so i was hoping that someone that did would be able to advise on weather it would be good or not. Thanks for all comments.

thinking:
lord d weapon

at lest 3 10 man csm units
maybe 2 cultist units as a meat shield

some obliteraters
and maybe some havocs

[Learn2Eel]

That would be fine, and you would easily fit that into 1500 points.

Just remember, the only Daemon Weapon that you can get (unless you are a Khorne Lord) is the Black Mace. It is 45 points and only AP4, however it has Fleshbane (always wounds on a +2) and if you cause an unsaved wound, the model that took the wound has to take a toughness test or die. In addition, if you cause an unsaved wound, every enemy model in a bubble around you must take toughness tests or suffer a wound with no saves allowed.

The Cultists will be ok, just keep them in maybe 20 man squads so that they aren't too expensive. I presume the Chaos Marine squads are in Rhinos as well? Give them two special weapons if that is the case, preferably two plasma guns/meltaguns or a mix of both. If you want Chaos Marine units as objective campers, then consider Noise Marines with Sonic Blasters and Blastmasters - they are also very good in this role and will punish MEQ and hordes alike.
Obliterators and Havocs are the best source of anti-tank as far as Infantry models go, so they will work well. Just remember, the Mark of Slaanesh on Obliterators will only be useful if they run from combat so they don't get swept.

You should have a sizeable chunk of points left over after adding those units in; Chaos Bikers and Raptors are good flanking units that can do some real damage and are cheap too.