I'm waiting to hear from a local ultra-marationer. Check out Sage to Summit in Bishop.
http://sagetosummit.com/index.htmlThey specialize in distance running; they've become the local focus of ultra runs, equipment, and advice. Give them a call; they'd be glad to advise you.
You might try contacting Kevin Sawchuck; he ran the JMT in 93 hours. He ought to have some good advice.
http://www.usatf.org/athletes/bios/MountainUltraTrail/Sawchuck_Kevin.asp