RE: Dall Sheep
shot my ram up there a couple years ago. Havent done any really intensive sheep hunting up there other then a couple fly out floats looking for sheep to go after with the wife (more intending on bou hunting but still hoping for the white critters).
As far as gear....get the best obtics you can afford. I would get all polyester/polar fleece. For rain gear, helle hansen. In the brooks I wouldnt think you would want plastic boots as the climbing is much much easier then the wrangles or from what I have seen/heard of the chugach mts. NO COTTON, PERIOD< NOT AN OUNCE!!!! Start hiking now with your gear and get comfortable with it. Find the lightest stuff you can afford (sometimes light and good doesnt come with a high price tag!) Start trying to look at rams, know what you want as far as horns goes. Know what is full curl, what is broomed, and what is a sublegal sheep. Learn to judge them (mass-length). Also Tony Russ's sheep hunting in Ak and Duncan Gilchrist's book The Quest for Dall Rams are 2 great books to pick up on the subject. They can go over gear, how to's what to look for with plenty of photos, what not to and what to expect!!!!
Also who are you going with? Deltana outfitters? Did the guides send you a packing list yet? I would go by it! Get the best you can afford and you wont go wrong!