I would actually not use either Dragon Claw or Thunder on a Physical set. I'd go with Wild Charge (that way you aren't having to put EVs in both Attack and Special Attack) and both Brick Break and Rock Slide. Where Elektross is going (UU/NU), there are not a ton of Dragons. And Rock Slide already deals with Altaria. So I'd go for better type coverage with Brick Break and Rock Slide. I mean, not like there is a huge power difference there either.