I would *not* start with the BattleForce box. Too few Khornes, too many
CSM (what? a unit of 8 and another of 7,
WTF?). If the units were 10 and 10, then okay with the rhino, but the Possessed
SM suck. This is the poorly put together box:
http://www.games-workshop.com/gws/catalog/productDetail.jsp?catId=cat440167a&prodId=prod1090186&rootCatGameStyle=
Just start buying squad boxes (khorneBs and
CSM are the better deals) or ebay lot auctions.
More than half my (still unpainted)
CSM army is converted BattleForMaccragge marines. I bought Chaos rhinos for my regular
SM, and have been using the chaos bling for conversions and terrain. So, if you're like most of us, you have extra marines laying about ... have them embrace the Dark Side! Particularly, adding bursting intestines for Plaguers is not hard with green stuff ... sorry no pix to prove that yet.
Khorne & Plaguers are the easy to play funboys. 2 or 3 rhinos.
DP hq, as kenshin620 said. 2 to 4 Oblits are the bees' knees and you've got a basic
CSM army.