I changed to a Mustang seat, big difference from the stock HD seat. I also use the Pro Pad sheepskin cover that are gel filled. I usually ride fill up to fill up without too much problem When I stop, I give myself about 10 minutes for a pitstop, rehydrate, and grab a snack if necessary. I have gone as far as 700 miles in a day once. My @ss could have went a little further, but I was starting to get 'punchy' after that. 500 miles a day is usually my average.
Might have to invest in a couple pairs of those bicycle shorts. I don't think I could handle commando. Might chaff a few areas I would like to use after I stop for the evening!