Consider the difference between the Valoredge and Sharpshot frames. With SS you'll be able to skill ranged and melee at once, but VE is much more resilient and will give you a focused skill up for melee. Also, the frame you select will affect which attachments you can fit, so mix and match them heads a bit if you like. Insofar as attachments, give yourself anything that makes him swing faster and more often.
For automaton melee, Coiler, Turbo Charger, Galvanizer~
Double attack (one Thunder Maneuver is 10%), haste (one Wind Maneuver is 15%), and yeah he can skill up on counters, too!
For Sharpshot make sure to include a Scope, and consider either a Drum Magazine or a Barrage Turbine (or both).
Consider wearing as much pet haste+% gear as you can yourself, like
Shaolin Belt,
Spurrer Beret, or and augmented
Anwig Salade (my favourite augs for that are pet: haste5/dmg taken-10%). Also, any gear that gives pet accuracy like
Karagoz Mantle or an augmented
Mirke Wardecors (mine is Acc/R.acc +15 and M.atk/M.acc +7 for the pet).
If you head into abyssea, Razed Ruin is a must. Then you can tack on Apocalypse or maybe Voracious Violet for DA/TA (or use Gnarled Horn for AGI or another r.acc atma like Drifter when skilling Sharpshot). I like tacking a strong regen atma on the end like Mounted Champion or maybe Stronghold just to maintain easier skilling for longer. Pachypodiums in Abys-Tahrongi are rather weak and will pummel your auto a good bit for counter to proc. These mobs should take you at least into the 360s, since people were capping skills on these at lv95.
Out of abyssea... Grounds of Valor Prowesses *may* affect your auto; and if they do, you can take advantage of increased skill gain rate from performing Grounds pages. Because of this uncertainty, I wouldn't recommend it because Atmas in abyssea are too potent to pass up for skilling.
Finally, you are the target audience of the Percolator. If you can't afford the out-of-pocket expense, strongly consider farming a few Obs for the attachment, or at least for money items to sell to buy a Percolator. I haven't used this attachment myself, but I've heard good reports from new PUPs about Percolator + Water Maneuverx1.
Lot's of luck and keep up with a very fun job!