No offense mate but you would be better off either getting a different Mas or saving up to pay for a newer Gran Turismo.
Some (though not all) 4.2 and some early 4.7s had several known issues and the last thing you want is to pay for a dud. Try to get something post 2010-2011 if possible as most of the kinks had been worked out by around 2012-2013.