Leica M 240 + 50/2 APO ASPH 'cron (if money were really not an issue for street shooting).

But if we're sticking Canon, then I suppose the 6D + 40mm pancake or 35/2 IS for 'discrete-street', or 70D + 40mm pancake or 55/1.4 Otus for 'street portraits' (where you want an effectively longer lens).