@Shredder
Please just take this as a different point of view and not a criticism, but I think it looks stunning as it is in that pic.
Black on Grey is the perfect combo in my opinion, and it's a colour i'd of been tempted with, but it just doesn't work for what I wanted sadly.
If you are converting it, are you putting the glass in the rear quarter ? because they will make a huge difference to what you see as a 'Grey Slab' if not, google image the Grey with full Black glass, and you will see it works really well. I think you might go to the extent of doing the handles, and it just looks like a lower spec T6 that's just not had it's handles colour coded, but could be wrong. (although the Black handles works well on the Orange T6)
Why don't you spend an hour with some Black insulation tape, and cover the handles. Then take a couple of pictures to study. That way if it doesn't work, you can just remove the tape, and it's not cost you a penny.
Also, have you considered the Edition stripe like I have? There now seems to be a few vans that have gone the Edition stripe route, and some of them look great, plus it really breaks up that vast colour you are seeing.
Again, just another angle from different eyes.