Ring of Sustenance. 2,500 gp exactly, and not only does this mean no need to eat or drink, but you only need 2 hours of a sleep a night. AND it allows spell-casters to recover their spells after only 2 hours of sleep (still only once every 24 hours, though). MAJOR benefit for an Inquisitor. Course, that means, you get to take turns on watch with the rest of us, but so what? If the DM in upgrading the item over time, there are a lot of good abilities he could add to this. Lots.
Anyway, that is my suggestion.
Master Arminas
Divine casters don't need to rest prior to learning their spells for the day.
Maybe Eyes Of The Eagle for a +5 Perception, making you *very* observant. :)
What deity you following? If you don't have a hard and fast preference look for one whose favored weapon is greatsword or bastard sword, since you gain the weapon prof for deity's favored weapon.
I'm running an inquis with a repeating heavy crossbow, and the DM allowed me to special order a magazine of abundant ammunition (3600 gp) so I have all the mundane bolts I can handle. I worship Kelemvor, Forgotten Realms god of the dead (LN) and his favored is bastard sword.
Check out the Scabbard of Vigor.
If that increases with level... how crazy might it be?
Unless you plan on casting a ton of offensive spells, you don't need 18 cha. I'd recommend 14 str if possible. Mostly for the to-hit on the Sword and damage for the bow.
Magic Item? Hmmm. Efficient quiver could be nice.
See if you can have a reskinned hand of the mage, with prestidigitation on it as well.
Useful? Marginally! Fun? Amazingly!
I'm planning to focus on archery but have decided to take the half-elf alternate racial feature ancestral arms to give me proficiency in a melee weapon (likely a two hander since my low strength seem negligible with all the damage/to hit bonuses inquisitor can stack).
I´d recommend an elven curvesword or a spiked chain, as you can use weapon-finesse on them, if you have the feat to spare.
Personally i find the inquisitor exspecially interesting, because he gets proficiency with repeating crossbows . (Actually the RAW say : repeating crossbow, in singular, but unless your GM rules the heavy crossbow out,) why not take one ? Style ?
Style ?
Speaking of which: May-be ask the GM for an Style-discount on a cloak or boots of elvenkind. Mechanically they aren´t incredible and with your Dex you dont NEED neither desperately, but if it grows with the character, it might grow to do other things, as well, if you want to be a hard-to-catch/stealth-god...
Other than that, either way, efficient quiver does jump in the eye.
If you want to go with 2 handed sword you should have higher strength otherwise it's really doesn't do much. As it is you can't take advantage of the 1.5 str damage and you don't qualify for Power Attack. I'd swap you Int of 14 with Str. That way you qualify for Power Attack and you get at +2 str bonus which means +3 damage. Grab furious focus and Dreadful Carnage that way when you drop an opponent to 0 or less hit points you get free action intimidate check and that what Inquisitors were built to do with 1/2 you level to intimidate. So you could rain down death from range then move action into melee drawing your two handed weapon for power attack giving you a +6 damage bonus. As well getting strong pull bow with +2 strength.
If you really want to dish it out go with 14 Wisdom and an 18 str, get bow to take advantage of the +4 strength and switch hit with two handed weapon. Put you level 12 and 16 stat boost to wisdom. The level 8 boost to Dex.
A Ring of Protection is nice too. The only thing is it doesn't stack with Shield of Faith.
I'd find a way to up your Con and Str, possibly by lowering your Wis or Int. What's your domain/subdomain/inquisition?
You get skills retroactively if you increase Int. That was a 3.5 thing that was changed.
also after looking at it I can manage to alter my stat array as many people suggested to look something more like this:
Str 14
Dex 16
Con 12
Int 13
Wis 16
Cha 10
If you're doing it this way, either find a way to raise your INT to 14 or lower it to 12, 13 does nothing for you and if you raise it later you don't get additional skill points retroactively.
I suggest lower to 12 and raise your Dex one, that way at level 4 you can raise it again and get +1 dex mod.
That point of int at 13 doesn't translate to 1 point at 17.
Put it in CON though. Raising that later WILL raise your HP retroactively.