Looking good, I would keep the speedo and tach central as these are the ones you are going to be looking at the most. Maybe bring the gps more central so you can keep an eye on it when navigating but keep it away from the compass.
Do you prefer your engine controls to be left handed? Mine are on the right hand side of my console which I have got used to but when I did my RYA 2 they recommended you keep one hand on the throttle all the time. I am right handed so when going into or coming out of a corner I sometimes need both hads on the wheel, does anybody else have any opinions on this? You however, may be left handed
Good luck, I have always wanted to set up a boat to my exact spec -I hope you get your 'ideal' boat at the end.