Would slightly later figures, perhaps from League of Augsburg or Northstar 1672 range need less work for the dragoons? (Haven't looked at either to check, but there are a few ranges of Sedgemoor/GNW/WSS etc that are around. Coats might be a bit long, but not sure).
Also worth considering if you will need mounted and foot versions.
Play BFaS in 15mm but don't field Poles, so can't advise on how often you might use mounted and foot, but most dragoons I've seen in action rush forward (mounted) in turn 1 and/or 2 then spend the rest of the game on foot.