The Hobie parts list shows using part# 8010201 rivets for the rear traveler track. This is twenty 3/16" x 3/8" CSK SS rivets (CCC 6-6).
You can get these rivets from your Hobie dealer, Murrays, Grainger, Fastenal, McMaster Carr.
For other parts like the padeye and pad for cam cleat, etc. go to Murrays four page interactive H14/H16 Parts Guide. You can click on any part and it will take you to the correct description and additional recommended items like rivets and screws. It also includes a table of all the rivets for your boat.
https://www.murrays.com/wp-content/uploads/2018/09/Hobie-14-16-parts.pdfThat is very helpful information. I can tell that the end of track on boat that I am trying to upgrade the traveler on has been riveted with different rivets as the rivet heads are slightly taller and larger in diameter. I had read these needed to be countersunk rivets. I haven't dealt with Murrays before but they have an impressive looking website.If the nosepiece of your rivet pulling tool will not fit all the way down to the bottom of the traveler track you can put some small nuts on the rivet's mandrel (the disposable part that the rivet gun grips) to make it work.
I like to use the Marson Model VHR-2 M79032 Heavy Duty Hand Riveter.
I found one of these for $80. After setting some with a cheap tool I think it will be money well spent if they are easy to set.