Hi Martyn
I can't answer all of your questions, but I can comment on creation watches. I have brought a Seiko diver from them and found the service to be excellent. Took just 3 days to arrive in the UK, with no taxes or duty to pay.
As for the MM300, I to have had the same calling (obsession!) for the past year. I brought a Sumo, hoping this would suffice. As great as it is, it's not the MM! One day it will be mine.
Cheers.
Si.