I suggest you consider the High Sierra Trail in Sequoia National Park. It is 72 miles long. You can do a round trip with a resupply point midpoint. Her is how we did it 5 months ago. Leave Crescent Meadows in SEKI (Sequoia National Park) on the HST (High Sierra Trail), when you get to Kern River, go south 9 miles on an established trail to Kern River Ranger Station, then head 18 miles East on an established trail to Cottonwood Meadows (there, hitchhike to Lone Pine, pick up your supplies at post office or buy them there), resume hike next day at Cottonwood Meadows, get on the Pacific Crest Trail heading north to Rock Creek Ranger Station (first night on resumption, stay at Chicken Spring Lake), next night Crabtree Meadows or Guitar Lake, then summit to Mt. Whitney, then return onto the HST back on the conventional HST to Crescent Meadows. You will be be resupplied this way at the 70 mile mark, and the hike back will be between 80 and 95 mile length depending whether you tangent from Crescent Meadows to Whitney or if you skip Whitney. We skipped Whitney this summer as we had done it the year before. Your hike will look like a rope lasso design. When you get 3 miles south of Kern Hot Springs, you will resume the HST at the same point you left it going south at the Kern River.
Another option is to go from Red Meadows on the JMT (John Muir Trail) to Independence via Onion Valley, which gives you 1 resupply point inbetween (John Muir Trail Ranch) at the midpoint, this is about 150 miles long trail.