Imperial Plate bracers and any of the Thorium armor that gets you a skill-up. The patterns for the thorium armor are pretty cheap at the AH usually, and the mats are mostly thorium bars and Un'Goro crater power crystals. The imperial plate is more expensive to make unless you've accumulated a large quantity of gemstones leveling your mining.
Neither of them sell very well - you'll have to find another expert to advise you on a profitable way to raise your BS level.
Thorium Bracers will get you to 280, although the last few points it will be a yellow attempt instead of orange. I still found that better than using an Imperial Plate piece though since the Imperial uses twice the thorium so I would rather do two yellows and gamble than a single orange. At 280 you can start making Thorium boots which I am hoping take me to 300 (only in the low 280s so far).
No matter what you make, it probably isn't going to be profitable. Just find the item with the least materials, make it, and send it to a disenchanting alt. From Leatherworking 270-300 I was able to about break even doing that.