I'd drop the heavy weapon teams from your squads, save maybe the CCS. While the weapons are useful, they're hobbling those squads' ability to stay versatile and mobile.
If you need the heavy weapons, drop two vet squads for a bare-bones platoon (special weapons on the PCS) and load up on HWS. Or try scout sentinels. Sure, they die fast, but at 35 points who cares? It's more targets for your opponent to have to split fire over, and they can tie up assaulters for a round before they reach your main line.
The russes are good until he assaults them, since he'll be swinging at the rear armor. An alternative would be medusas or (if you don't mind squadroning your vendettas) bane wolfs. For medusas, skip the bastion breacher shells; AP2 will deal with termies just fine. For bane wolfs, try them in reserve. Tie up an attacker with infantry, then roll those in and pick up the whole squad.
Here's an idea of what I mean:
CCS w/ Astropath, Lascannon, x2 Plasma Guns 95pts
x2 Vet Squad w/ 3 Meltaguns 100pts
- PCS w/ 4 Plasma Guns 90pts
- x2 Infantry Squads 100pts
- HWS w/ 3 Lascannons 105pts
- x2 HWS w/ 3 Autocannons 75pts
x3 Vendetta 390pts
x2 Medusas 170pts
It's less heavy support, but you don't need the big guns with all the HWS. If the Medusas don't suit you, you can use Bane Wolfs or turn the lascannon HWS into another autocannon and use two Russes instead.