I agree with GRN. Go with an 8'6" 5wt. There is an Orvis shop right in Last Chance. You say you already have the Orvis reel, check out the Clearwater. Full 25 yr guarantee (no questions asked) and there is no difference in the rod weight between a 8'6" 4wt. or 5wt. they both are 3 oz. Plus in the 5wt. you have a choice of 6.5 mid flex or a 9.5 tip flex with 2 pc. running $159. and 4 pc. running $189.
Just a thought.
FG