There's no difference. It's an MT6 for the front and an MT7 for the rear. As @ben_travis suggested, I'd buy two MT6 instead, or even the MT4 if money is short. You can get Trialtech pads for both now so the braking power should be even better than with stock pads.
I was gonna write that when riders like Ben are satisfied with an MT6, amateurs like us should be so too but then again, he rides really smooth and may not need as much power as we do, when not landing perfectly etc. But I am pretty certain that the difference between the MT6 and the MT7 is only marginal.
Having ridden the MT5/6 I'd still go looking for a new Shimano Saint 810. The pad clearance can be an issue once your rotor is slightly untrue. I had a rubbing SLX rotor on my Saints which was still ridable but wasn't with the MT5.