The Chilkoot River is a blast in July. Early sockeye, first of the pink salmon and good Dolly Varden fishing. Your 7 weight single hand rod is fine for pinks and Dollies, but a bit light for sockeye.
An 8 weight switch is an ideal S.E. Alaska all-around salmon rod. It has more backbone for fighting fish, the ability to cast either Spey-style or overhead, and the extra length to let you mend line and more effectively dead drift flies.
Sockeye really like a dead drifted small fly and an 11 foot switch rod would let you cover more distant runs and get longer drag free drifts.
Hope that helps!