I like to dry hop with about 1.5 - 2.25 for a 5 gallon recipe. On the lower end, you get a decent hop aroma, but, in my opinion, nothing overwhelming. I bet as an amber, your brew could take 1.5, maybe even a little more, and not get anything near a west coast amber. I find I need at least 1.25 to notice a significant difference.
Personally, I've had great experienced with Columbus, Amarillo, and Centennial for dryhopping. Centennial might be nice because it's in the same zipcode as Amarillo, but different enough to bring it's own flavor to the party.
Anyway. Good luck with the competition.