I was your friends same height and weight a few years ago and close now. My first bike was a Raleigh M60 mountain bike. Great bike the dealer helped with a few adjustments. I took out that day on a nice long ride (about a mile) and thought I was dying. I took the bike back the next day and told the owner something was wrong with my seat it felt like an axe. He just smiled and explained what my sit bones are and if I had not ridden in a long time I had to train them again. He told me to go ride ten rides after that we could look for a different saddle. After ten rides I didn't need a different saddle.

That bike was stolen I decided I wanted a road bike. The dealer I ended up buying from sold me a Specialized Sequoia elite. It has been a great bike but I have never been able to get comfortable on long rides. I have changed the saddle and seat post, the rear wheel was warrantied due to cracks. I have never broken a spoke so far.

I did realize after my purchase I wish I would have been patient and ordered a long haul trucker. I rode one a year ago and definitely felt better.

Good luck and let him know it's ok to stop and rest as often as needed in the beginning. He is going to have a sore butt in the beginning. It does get easier.