Thanks! I'll try to update the new build to reflect your input as well as the recent mastery changes.

Forgive me for being longwinded, but I want to be thorough. First, thanks for posting this. I'm going to tell you what I disagree with and why.
Masteries - I would max Good Hands and Awareness, and lose points in Expanded Mind. It's a minute amount of mana, but less time dead and faster levelling is what will give you the edge. Not the extra 23 mana (I'm sure some will agrue).
Instead of force seals, I would recommend straight potency for early game effectiveness.
0.9 AP per level is nothing, might as well cash in as much as possible early for a small edge. Where you DO want force runes, is in your glyphs. 1.5 AP per level is definitely going to go a lot further than 5 magic pen.
Now as for your item selection, I've played a lot of games both classic and Dominion with Brand, and one stat he NEEDS is cooldown reduction. Instead of dropping 975 on a Prospectors Ring, buy a Ruby Crystal (makes up for that HP, and you can later turn it into either a catalyst OR the Kindlegem you listed), an Amplifying Tome, and your ghetto boots. Whenever you return to shop, convert tome to a Fiendish Codex, then a Morello's Evil Tome. I'd also wait to upgrade your Hextech until AFTER your Deathcap. Getting that deathcap is definitely more important than an extra 10AP and slightly more HP return. All of your other items I agree with, though the Hextech Sweeper is situational.

Thanks for posting this, I never thought to even buy a Sweeper before reading this.
GL HF!

EDIT: Something I failed to mention. You only want one point in Sear for the stun until you're forced to take it later in the game. It's the toughest one to land (creeps, other champs block, ect) Your W and E are your mad damage dealers and you want to lesson the CD's and increase their damage asap.

But maybe I'm just crazy.