Hi Scott,
Get one and check it agains the size of the Britains figure scale to scale do they look good together. If not you could also try Frontline they do some downed Cavalry with the horses in a similar position. I have a few of their figures and they seem to go well with the Britains figures. Plus they did a line for the first Sikh War and the tack is clearly British and would probably work in Natal.
Dave