Hi, let's get a basic roadmap going.
Phase 0 will just be a simple msf module, that hosts a web page and tries the modules currently implemented in metasploit (this sounds like a decent MVP)
Phase 1 will implement the rest(mostly from exploit-db)
Phase 2 gets a decent infra behind it, with logging (this will be needed, as attempts will have to be recorded (succeded/failed, which exploit, etc)
Phase 3 could be a basic auto-escalate tool, but let's cross that bridge. when we get to it.
I hope, it's something resempling your original plan.
Skype handle: mgaborl
Cheers,
Gabor Mate