I usually make 6 gallon (23 liters) cheeses. So they are easier to age for longer. They are almost always natural rind--depending on the cheese I either just let the rind grow pretty much as it will with the "inhabitants" of my caves, or I brush it, or sometime they get oiled. I vac the the natural rind ones after I cut them open the first time, so usually after a few months. It's much harder to do that with only 8 liters because the surface area to internal paste ratio is so much greater.
But what I would recommend is that you try to age it as a natural rind for at least a couple of months keeping the humidity above 85% and THEN vac for whatever time you want. Not the other way around. You want to develop the rind in the early, formative stages of the cheese not at the end.
Best of luck. Keep us posted. Pictures!