PF 1e Help gear bound planatar

[Efrate]

Since I had to send my bound solar back since the the demon lord incursion is gone, I bargained with said solar to get a previously bound plantar as a now semi-permanent minion. But as the party is now level 19ish, ol' planatar is lacking in the combat area. Spells are easy enough to fix, but he lacks in combat effectiveness, so I want help gearing him up.

Currently has his +3 holy great sword, ring of protection +5, amulet if natural armor +5, cloak of resistance +4, and a few minor things like a pair of apprentice cheating gloves I had laying around etc. I have approximately 200k to craft or buy gear to make him a more survivable and a more credible threat. Party is 19th level ninja, diviner 19, and sorcerer/dragon disciple 19.

I have craft arms and armor, craft wonderous, and craft construct with enough + spell craft to hit any DC even if I do not know spells. Barring magic armor, and stat enhancers how can I get this downgrade up to about our CR and being a meaningful combatant.

I can have him always hasted and greater heroismed, and likely diviners fortune frequently for most encounters. His spell list will be some buffs, condition removal, and a few heals.

Suggestions?

[Drelua]

Well, outsiders aren't proficient with armour unless they're described as wearing it, so unfortunately it's not proficient. But, if armour doesn't have a check penalty, it doesn't matter if you're proficient. So get a set of +5 mithral kikko armour. Kikko has an ACP of -3, so mithral brings it down to 0. That's +10 AC for 29,500 gp, accounting for the higher price for large size armour.

[Efrate]

Its magic, I would make it medium and it would upside. Good call. I might have up to 430k gp, I dont really need to buy a staff of power I guess. Just swag points. Next leg of adventure is against a variety of great wyrm dragons, expecting cr 22 to 26 or so.