I love that area. I have never done that exact hike though. I have climbed middle sister from two different directions and it is beautiful. You are on the rain shadow side of the cascades, so humidity is not your problem. Depending on the snowpack/melt and when you go, the mosquitos (mozzies) are terrible! You will covet the WWBB built in bug net. The ponderosas (p- pines) are not as big as the West side trees so a standard 6' tree strap/6' whoopie setup will be fine. I plan to hike the PCT in that area south to Waldo lake this summer/fall. Have a great time!