Finally my first Hector

I think any set used on regular Hector will work, though I think you're best using those IVs for an enemy phase build. Hector is going to want Bonfire/Ignis/Aether(Aether is here since Berserk Armads will charge it faster), Swap for Assist skill(usually the best choice for an armor unit), Vantage 3, Wary Fighter 3, or the expensive-yet-satisfying Vengeful Fighter 3 for B-skill, C-skill can be a Threaten skill(Defense for more killing power, Attack for survival) or Ward Armor(for armor teams), and seal would be Quick Riposte(for Vantage and Wary Fighter) or Distant/Close Defense(for Vengeful Fighter).

Hope this helps you out, now I need to figure out the best set for my Atk+/Res- LA!Hector.

Lots of ways. Vantage, Bold Fighter, or Wrath for his B, QR or Armored Boots as his Seal. You can even run him with Warding Breath if you're not going to run him in Armor Emblem. He rocks out a nasty Aether as well, which pairs well with any build, but particularly on mixed, due to lack of Wards.

You'll hear a lot of people tell you that giving up DC for Warding Breath is dumb, but this not only gives him 31 resistance, but would lower his Aether to fully charged. With Vantage and Armored Boots, he can trigger Aether with Wrath boost, healing back up to full, granting him that extra movement again. Hell, switch out Vantage for Wrath for an extremely busted Aether.

This isn't what I'd call him optimal build, mind you, but it might fit the role you need him to. I'm currently running mine pretty boring with Aether, Vantage, and QR Seal, but I plan on giving him lots of different builds for different situations, including the above mentioned.

The extra Res from the boon will help him better against mages so it's not a bad IV at all. Any IV Hector can benefit from the same builds as regular Hector. Still the most useful ones would be his native DC of course and Vantage. You can worry about utility later on but you'll definitely want to run QR seal because he doesn't have it in his weapon like regular Hector and you're already using Vantage for B skill. But if you kept Wary Fighter on him, you can use another seal.