Kinda depends on his current workload and if he has all your desired supplies in house, but I think his goal is the 3-4 month mark.
Both of mine were much longer than 3 - 4 months, but I was essentially buying the first ones. Rob is pretty good about delivery dates. spade2you is right - if his workload isn't insane and he's got everything, it's pretty easy.
Just ping him and ask ...

