Join the Yahoo "hiker" group. That is devoted to the SHT and there are lots of trip reports and there is a spreadsheet in the files section showing mileage, access points, restaurants and grocery stores near the trail etc.

I hiked it and averaged 10 to 12 miles per day going old and slow but a lot of people do 18-20 miles per day. Interesting trail but not a remote wilderness experience. I recommend that you give it a try.