Personally I would return the motor and get the version designed for 10S. The motor you have will work on 10S but will be considerably down on power.
Agree that you should seek out pattern flyers local to you
I haven't used Alibaba so cannot comment on using them, surprised you cannot get the ESC from within the US, where did you get the motor from ? - F3A Unlimited, Aloft hobbies & NorthwestRC are the listed Dualsky US retailers.
Although common in IMAC it's not common to run a central box in pattern, primarily due to weight considerations also pattern planes don't require such power hungry servo's - just precise and repeatable ones !

Steve