yeah you shouldn't have any problems with customs. I bought 5 pounds recently from Hops Direct. Paid $45 for shipping IIRC. Customs inspected 2 of the bags (just broke the seal, nothing major) It's the way to go if you want plenty of the same variety.
However it does create a false economy... i've done 2 pretty big IPAs in a row, which i wouldn't have done had i been paying more for my hops. :blink: So in essence it hasn't "really" saved me money... just enabled me to do something I never would have done in the past.