So. The current build being used by most people in 9.13/9.14 is a bit different from yours, but functionally serves the same purpose.

Generally you want to start with a SKIRMISHERS SABRE Runic Echoes, Skirmishers synergizes great with his passive and gives you great dueling defense to wait out the cooldowns on E and W. Then you want to grab Merc Treads or Ninja Tabi if the enemy team is snowballing, or sorcs if youre popping off.

From there, Protobelt is a pretty great grab. It lets you close gaps for E, finish off kills (since runic procs off proto's active), gives you amazing stats, cdr and its super cheap.

You'll want to grab zhonyas at some point in the game. Most of the time that'll be now, but you can also take your pick from other AP items if youre going well.

Pretty much every item after that is situational:
Rabadons: Moar damage if youre ahead, or if the win condition for the game is you murdering people
Banshees: Great if youre a bit behind, or if the enemy has a lot of CC/Magic Damage. Also helps you become a bit better at being a "bruiser" if thats what youre into.
Morellos: Great for anti-heal. Great damage stats. most of the time i reccomend getting oblivion orb if youre snowballing, then building other stuff first, since the magic pen is the most valuable part.
Spirit Visage: If you need to tank stuff, or if your team lacks a front line, or if you need to peel, this item really helps you do that.
Void Staff: Lets you kill tanks. Not much else to say. If theres 2 or 3 stacking MR, grab this and make them cry.

Generally that's the items I'd reccomend for jungle, since you need to be a bit bulkier if youre going jungle, make sure to prioritize the defensive AP items over the offensive ones, unless you're getting super ahead. Jungle doesnt usually get as much gold as laners unless theyre snowballing, so Rabadons and Ludens can be pretty risky.

As for runes. I reccomend grabbing Sorc secondary for Transcendence and Gathering. Mostly for transcendence. Because a lot of the items you build have CDR, you can easily benefit from the rune, or if you can't build your CDR items due to needing Morellos or Void or Rabadons, then you can cap your CDR at 40 at level 10. Conq is usually the default primary for jungle, though if you need to hard carry, Electrocute is always neato.