Do you need another attacker? Snorlax is a top tier defender but there are much better attackers in my opinion.
I'd go with the 1716 if you have the candy. The 1484 is simply too low, you'll run out of candy at some point. The 1716 is good all around, with the best defensive move set. I'd want a Snorlax for defense to place high in gyms and deter attackers. The 1978 will still be strong enough to attack with despite not powering up. I'd keep all three of the 1800+ ones while powering the 1716. I'd drop the 1484 for 2 candies during the event unless you legitimately have loads of candies to power it up someday. Although I'm probably being a hypocrite, I had 4 Snorlax, dropped the 42 and 131 but kept the 1409 and 1696 thus far. 1409 is 91% IV Lick/Body Slam, 1696 is low IV with ZH/EQ. I don't know if it's because I don't have a good one above the 1409, but I can't make myself transfer it for double candy.