Actually a HOB filter is likely to cause the opposite prob, not enough turbulence. You need water movement at the surface to give good aeration, and females bettas with their minimal finnage are ok with reasonable currents.
I think richgroup may be refering to males when he says bettas have problems with a current.
Obviously you don't want huge currents round the tank, but so long as you've got some reasonable movement at the surfance you'll be fine. Saying all that, they are labyrinth fish and so tend to take air from the surface more often than not. So minimal movement should be ok, so long as the filter is actually capable of processing the waste.
What filter is it you were thinking of using? as in model.