We know Meliodas, Diane and Ban already.
MERL/MEPL, going by conventions there's a fair chance that she'll be the sin of lust yeah.
(K)IN(G), I'm thinking that the poster is at least right that he's a heavy guy so I'm going for the sin of gluttony with him.
(C)AN, not sure. Sin of pride maybe.
...VI..., sin of sloth since he's too lazy to take off his armour.