i still very much like the aussie model. you have 5 or 6 state/province or maybe in BD's case city teams, then within each of those you have about 15 maybe even 20 club teams and within each club there are about 6 different grade teams. give each city an academy team and a 2nd xi team as well as their #1 team and then you should breed players who've gone through the hard yards to get where they've got and also players who have played alot of cricket even if they are only young.
the other thing to do is to have regular A team tours where they player the strong state and province teams wherever they tour, BD should also compete in the emerging players tournament and if possible send a team to compete in the icc intercontinental cup (preferably an A team or development team). imo that would be a good structure, other things to think about are better qualkity facilities, umpires, management and creating an environment where players develop a certain attitude which will help them develop and perform as cricketers.