Fantasy -> 40k basing

[DWest]

I just picked up a Fantasy Slannesh Lord for use in my CSM as a Chaos Lord w/ Daemonic Steed, and I'm wondering what kind of base to attach. The model comes with a 50mm square, but most cavalry come on that 25x60 hot dog bun base if I recall? Should I go with the base as supplied, even though it's Fantasy, or should I rig up a different base to match the type?

[ScrutMaster]

If hes a chaos lord and counts as termie armor, use the normal size base that terminators do. If I recall right there is no wargear option for a Daemonic Steed in CSM Dex. You could use a dreadnought sized base and be fine though. It's not really a modeling for advantage in my opinion cause the bigger base just means you'll be in range of the enemy just as easilly as they of you.

[DWest]

http://www.games-workshop.com/gws/catalog/productDetail.jsp?catId=cat440026a&prodId=prod1050024&rootCatGameStyle= is the model in question. As I'm assembling the model, the serpent body is a fairly large coil; I'd prefer to attach it to the 50mm square if possible, but since the model counts as Cavalry (Mark of Slannesh + Daemonic Steed), would I have to put it on a bike/cav base instead?

[gwensdad]

I'd see if it could fit on a standard cavalry or bike base, since that's what Seekers are mounted on now.
If not, try 40mm round.

[BuFFo]

It'll fit on a 40mm round base just fine.

The model is too wide to fit onto a bike/cavalry base.

[justsam]

my mounted tzeentch heralds generally end up on cav bases, since they go on screamers, which count as jetbikes. of course, i've got the weight distribution issue to worry about too. screamers are pretty well balanced for the small flying bases, but not when you try to tack a chariot onto the back of it.