You’re more than welcome we all help out each other whenever we can..
your MM will do great on 4s no worries,

you might want to think about adding a fan and doing mods to it later.. Just a thought..
Jordan is you man on the Center diffs too.. here's link to them if you want or watch Ebay they have some XT8 and 808 center on there now of sale
http://www.amainhobbies.com/product_...oducts_id/8633
You will also need some of these..
http://www.amainhobbies.com/product_...oducts_id/8629 or Ebay for a better buy..
Best of luck again should be a fun build..
Bye the way thanks for the compliments..