Keep in mind that the release of Choice Items will change a lot

When the release of Choice items does eventually come, remember that a lot of stuff will change. Currently Life Orb is the go to pvp item. That will change with the introduction of choice items. Remember, it will benefit everyone to go back and edit choice item sets into your posts!

Life Orb and Leftovers, mind you. Especially because you can get multiples of the latter for CHEAP.

Choice Scarf Drilgann is OP

Choice Scarf Drilgann wouldn't actually be all that great. You would be giving up his mega evolution and choice scarf is only a 1.5x boost, meaning his speed stat would be 160 (at lvl 50), which would be out-sped by a Mega Electruxo (speed of 162 at lvl 50). Basically, it would be better to run a sandstorm team to double his speed and get the Mega Drilgann speed and attack.