Dragonite power up?

I would wait till you have a dragon it's with the optimal attacking or defending moveset.

If you really need a defender ,you should power up one with the high iv and don't care about the optimal moveset. From my experience, HB and DC aren't that bad it just depend on who you fight with if you fight with who dodge everything DC is really nice but if you up for ppl who don't dodge anything HB is good. DP is average, it like a half way for both move.

I'm still 21 Dratini candies away from evolving my Dragonair so I can only give advise as someone who's attacked them.

I'd go for sw/dc

Since the IV differences are quite literally negligible, I'd probably go with the SW/DC. Two reasons for this: 1. HB is one of the easiest moves to dodge in the game 2. If you ever choose to attack with this Dragonite, DC is much, much, much more useful than HB.