750 list - just getting started, and looking to expand

I'll hopefully be getting my first game or two in with my Dark Eldar tomorrow, and I've got a list to try out that I'm hoping will be enough to get me a general feel for the way the army plays.

Archon, Shadow Field, Huskblade - 125

5 Incubi - 110
Venom; Splinter Cannon - 65

14 x Warriors, Sybarite, Splinter Cannon, Blaster - 161

9x Wyches, Shardnet/Impaler, Haywire Grenades, Hekatrix, Power Weapon - 138
Raider - 60

3 Reaver Jetbikes, 1x Cluster Caltrops - 86

745 points all told; hopefully its a decent mix of units and is reasonable on the tabletop. I am painfully aware that there's not much anti-tank, hence the haywire grenades. Hopefully there won't be much in the way of mech at such a low points limit, and the grenades/blaster/raider lance will have me covered.

All I have to work with at present is the battleforce, an archon, a venom, and a box each of Incubi and Warriors. I know I need more transports for the warrior squads, but in the interim I'm just going to blob them as cover-hugging objective holders. I have 175(ish) points set aside for a Razorwing with upgrades, and aside from that I'm looking for other advice on how to expand this out to a competent, kabalite themed force.

Looks decent but I'd personally go with 4 incubi, put the Archon in the Venom and cause havoc with that.

Consider throwing a Heat lance on the Reavers instead of the Cluster Caltrops. You already have quite some anti-inf in a 750pt with the warriors and the Venom itself.

If you will be cover-hugging objectives with the warriors give them some anti tank threat instead. They won't all be able to shoot at that nasty Rhino going right for them, but at least you have a chance of opening the can before it hits you.

I'd personally field something like this:
Archon, Shadow Field, Huskblade - 125

4x Incubi - 88
Venom; Splinter Cannon - 65

11x Warriors, Dark Lance - 124
10x Wyches, Shardnet/Impaler, Haywire, Hekatrix, Power weapon - 210
Raider - 60

3x Reaver Jetbikes, 1x Heat lance - 78

Archon + incubi up a flank together with the wyches.
Deploy the warriors in cover where you've already placed an objective.
The reavers should go up which ever flank your opponent will be driving his vehicles.

At least thats my 2 cent

I'm at a similar stage to you, maybe just ahead with about 1250 worth of units.

For new units, definitely get a Ravager in there. There aren't many competitive lists without at least 1 of these. Load it up with Dark Lances and go hunt some tanks.

Then pick up another battleforce and another raider I'd say. You've got 2 more transports, some more core units and 3 more Reavers. Reavers are really good, but having only 3 means they just won't last long enough. They are an easy target for your opponent to pick on.

If your still short of anti-tank, give your Reavers some heat lances or Blasters. I prefer Heat Lances as they have more killing power on a tank, but they have less range for full effect.

I like the list, except I agree with Hess, throw those 4 Incubi in a venom with an Archon and your opponent will HATE life, whether it's 10 Bezerkers, or 30 boyz. If you're going for Kablite based, and don't have enough AT (anti-tank in case you didn't know) replace the wyches with 4 Kabalite trueborn with 4 blasters in a venom, or maybe 2 squads of them in 2 venoms, either way, if you have the Incubi, you're pretty covered for close combat, and with a Kabalite based army, chances are you'll shoot your enemy to pieces before he gets anywhere near you. If you don't have enough points for the Trueborn in venoms, take the venom aways from the Incubi and give it to the Trueborn. You can keep the Incubi behind cover or in reserves, just wating to lash out at a nearby enemy squad. That's what I did with 9 Incubi and a Archon in my game last night against a Khorne army. They came in from reserves and WRECKED a squad of 16 Bezerkers. Kabalite themed lists, at least from my experience, just usually sit on objectives and shoot at stuff. So if you do that, you can keep the lances as well, but if you wan't to be aggressive then take splinter cannons for sure, and lots of vehicles that can sweep in and out, leaving nothing but the writhing corpses of your enemy, their souls screaming in agony as you peel their skin like bannannas and absorb the souls within.