Well here a two different £8 links... (disclaimer I'm not recommending either)Warhammer Space Marines Horus Heresy Betrayal at Calth Board Cards Rules Dice |Warhammer 30k Space Marines Horus Heresy Betrayal at Calth *NO FIGURES* | eBay
I've ordered from one of them so looking forward to seeing how it works.
The 'good' side:
1 Hero (ideally Terminator armour)
1 5 man Terminator Squad including Sergeant and Heavy Flamer
1 10 man Tactical / Veteran Squad including Sergeant, Special (Flamer, Melta or Plasma) and Heavy Weapons (Missile Launcher or Heavy Bolter)
The 'bad' side:
1 Hero (ideally Chaplain style)
2 * 10 man Tactical / Veteran Squads as above
1 Dreadnought (ideally Multi-Melta or Assault Cannon)
Now from what I'm reading you kinda choose what your Sergeants and Terminators are equipped with, and it's your choice of Special and Heavy weapons in the Tactical / Veteran Squads.
So the Dark Angels from Dark Vengeance give you all of the 'good' side, if you count the Company Master (Captain) as your Hero in Terminator Armour, the Plasma Cannon as a Missile Launcher and your Assault Cannon armed Terminator as a Heavy Flamer instead! Similarly with Assault on Black Reach.
The Chaos Marines from Dark Vengeance nets you your Hero, Dreadnought and 4(!) Sergeants (you only need two but they're all equipped differently) and 2 Tactical Marines, so you'll need to buy 2 boxes of generic Chaos Space Marines. And amusingly you could instead use Assault on Black Reach to give you the bulk of your 'bad' side, as it contains your Hero, Dreadnought and a 10 man Tactical Squad, all you need is 1 box of 10 Marines.
Given that I've got both... I feel I'm onto a winner