Sounds like a great trip!

With that kind of budget, definitely look at REI cycling sale racks- Sugoi and Pearl Izumi have some amazingly lightweight stuff. Marmot Precip is also great, but a bit heavier and takes up a bit more space. You can also get some good prices on 'last year' models, but I don't recall when the 'new' season stuff comes out.

Depending on your size, also check out the kid's stuff. I'm just small enough to (sometimes) be able to wear a kid's L-XL. You can save big bucks that way.