First, Chakax is probably not a points efficient choice for what you've got currently. One of his major abilities requires there be a Slann, which you obviously aren't going to have at that points level. For that matter, a tooled up scar vet would probably get the job done for a lot less points, although it looks like you're taking a more expensive character to fill points. Sure a scar vet doesn't have some of the abilities Chakax does, but most of those are overkill at less than 2000pts, IMHO.
As far as units to get, at higher points level you're going to want a wizard, if for no other reason than dispel scrolls. Either a disruption unit (e.g. terradons, skinks, chameleon skinks), or more shooting (e.g. salamanders, razordons, ancient stegadon, more skinks), should probably be your next priority, followed closely by magic.