AOC
I have been involved in a few start ups as well as some re-engineering and presently have and operate on an AOC.
The process can be lengthly and the financial commitment is enormous. Go in with eyes open and expertise around you. Get to the CAA and have a good Pre-Application meeting and add a minimum of 20% onto any dates given. This is the least I can say, the list of do's and don'ts can be long but you will be guided.
Boeing can be a good source on the B777 with a view to what they may have in asset management, as well check with the banks that usually hold the leases.
Good luck, it's a challenge