I wish Graupner actually knew the max. efficiency of their jets, it's ridiculous. That does sound like a good setup joccee, if the motor turns too fast you can just decrease the cell count further, though with a kv of 4400, decreasing below 6c, will well drop the rpm's a lot. So yeah that exact setup sounds good.

BTW, I worked on my variable nozzle today, I've got to go to work, but it's all mocked up and ready to solder..