power up low level Snorlax?

Definitly not. The 95% one is too low CP and offensive moveset. Focus on XP and candies, you will hatch or catch anothers with moveset A to defense and high CP/IV. Keep around with both 71% & 95% to training gym and transfer the others.

You don't have enough candy to power any of them up. Just wait and use as buddy.

Will take too much candy before they become relevant in gyms. You're better off waiting to get one at at least level 20.

Too much candy sadly.

I'd keep them all. Snorlax are super rare & it's 1 extra candy only to transfer them during the event. You could walk 1.25K during the event and get a candy ... so the opportunity cost of holding on to them is tiny!

I'd set one as your buddy immediately (unless you have a really good Lapras you want to finish first) and amass 100 Snorlax candy or so. Then .. if you haven't found a better Snorlax, start raising the 95iv one. Yes, it's more of an attacker than defender, but it'll still be at the top of many gyms & take forever to kill cause it's still a Snorlax.

I guess Snorlax is not really as rare as Lapras. But if I have to choose I will pick the 95% with A grade attacking moveset.