I am looking to buy an IVOProp for a 912-ULS motor. I think what I need is a medium 70" however, I have the tall grove gear so could use 72". Would that be advantageous? Also, how long of an extension would I need for this setup? I think a 2" but am not sure. As well, are there any recommendations for the spinner?

I haven't called IVO yet to get his input because I wanted to get some input from TeamKitfox first.
Thanks,
Fred