Okay - I think this trip would work. Still working on dates, but I'm thinking mid to late July to mid August.
Taylor, this trip should have good fishing from day 1. Long Lake early on is known for big Browns & Rainbows - not as much for numbers & it does get pressure, so they aren't always willing to bite easily. Beyond that, though, the other lakes before Bishop Pass have very willing brook trout among other species. At one inlet, I caught a brookie, a rainbow & a brown on 3 consecutive casts.
Over Bishop Pass in Dusy Basin is the chance for goldens & rainbow-golden hybrids, possibly large fish.
From there it's new territory for me, but the streams & meadows promise excellent fishing & breathtaking scenery, framed by striking peaks. It's one of the most beautiful stretches of the JMT - Big Pete Meadow & Evolution Valley further North. A couple lakes, too - not sure how they fish.
Then Darwin Bench & Lakes, with golden trout & the chance for some big fish if timing & luck are with us.