You are going to lose your shirt with a G2.... we have operated G2's and G3's, right now they are sitting on the apron and we cant even give them away
It is apparent that you know nothing about the costs of an aircraft or maintenance, so be very careful as you are running the risk of bankrupting your company.
To jump from airline flying to corporate ownership of a large jet is utterly crazy. I would strongly suggest getting an aircraft share in Netjets or similar to gain the experience of corporate flying, then in a year or two, reassess the costs and decide if you can afford a "reasonable" corporate jet.
Mutt