I for one would not think of an MK65 when asked for the most forgiving kit.
As far as I know, a Metrakit is a good kit, good speed, but not at all forgiving. And if you do fuck up and you need to get a new piston, they're twice the price of a regular Airsal or something.
I would go for the good old Airsal, it's a good all-rounder, it's fairly quick, very forgiving, reliable and cheap.