can you not purchase one yourself? If not I'm prepared to purchase one and lease it to you if that's possible:
Update, there seems to be no way to purchase an the A225, as although it appears in the aircraft database, it is not available to purchase as an out of production aircraft, current aircraft, or aircraft leasing.
Other airlines do have single examples, my best suggestion would be to contact them and ask if you can buy/lease from them... thats the best I can offer
Further update
There are lots of entries in the forum about this aircraft type; I suggest you check them out and then contact admin and request one... our airline has no use for one so it seems pointless us asking for one, if there is only 1 allowed per airline and only by admins if you request one. There is also some tweaks to the .cfg file apparently that have to be done to make the fuel flow correct and ensure that flights don't get rejected