Just a note here, but both your request and your requirements are a bit out there. Having been a developer for StarQuest, an old spaceship server that used Movecraft, I can say it was one of our most complicated plugins and also one of the most laggy. We modified it heavily, but that work was not easy. Also, most developers are not willing to sign on exclusively to a server. We usually are good developers because we have worked and do work a lot of places. That's what gives us experience.
A "cooler Movecraft" with internal weapons, an engine system, speed requirements for landing... I can tell you that you may well want to write a new Movecraft for how difficult those requirements might be. How big of ship sizes do you need, what kinds of vehicles (ships, planes), etc? More specifics needed.
Additionally, you offer 20% of the profits, but do how much money is your server actually making? I'd need to see some figures before I even considered this.
