Sure. If you want them in series, just connect the + of the controller to the + of a Deans, then the - of the controller to a - on another Deans, then connect the 2 Deans with a piece of wire.

would that connection give the longest run times?

the more i think about what i want this truck to be, it only has to be fast enought to beat my dog (sheltie) so anything over 20 will probably do.

New goal is long assed runtimes. Will dual packs provide the longest times? I assume in association with a higher turn motor and the most efficient esc?

Well it really depends on batteries. Would you run LiPo's? or NiMh?

probably lipos. from everything im reading they are the way to go.

How many cells? 4S, 5S, 6S?

hmmm.. as many as physically possible? :)
I'm on a pretty unlimited budget at this point, so I want to pimp it out.

I will be using the superbrain 989 ac/dc charger (indoors) so my cel limit is dictated by that.

I would go for 6S.