Welcome to the group.
If you are looking for used bikes, test fit a ride at any place you can find a bike.
Seats can vary alot.
I sat on a newer OEM seat and a broken in OEM seat and they differ by 3-4 inches.
I found a bike with a seat with footpegs and a seat with the floorboards are seriously different.
I'm the taller with the waist to helmet height and a back rest makes a big difference.
I have really bad knees and with the floorboards, any seat worked better.
All years of manufacture, I found the "hard" fit issue was the bars.
Check all of the bikes for "risers". You get about 1.5" up and back with most.
I bought mine without and it fit OK, but after 3 months I added the RIVCO risers and they make a big difference.
If you are extremely crafty, you can rebuild and newly engineer, anything.
There are tons of normal ready made accessories and add-ons out there and there are people here that have almost built the bike "NEW" from the engine only. This is an amazing group of people that can help with everything.
Welders and carbon fiber manufacturers don't have a prayer against some of the guys here. Body shapers and painters, etc., same.
You'll find that there are as many opinions as people on this forum, but within the group, I can't think of anything that someone doesn't have first hand experience or better.
Mechanically, the expertise is better than the direct Triumph manufacturer.
Add ons, for any style are all over the place. there are lots of facts in the "how to" forum thread.
Bags, handgrips, back rests, tires, SEATS, anything.
Try the search feature and if you dont get the answer you are looking for, throw it up on the General Chat, and someone will answer.
One thing that you'll find quickly. There is something to the # of posts in the avatar column and the member since date, but the knowledgeable guys will let you know.
Look for the experienced viewpoint.
If you read all of the postings, some in the group don't actually OWN a Rocket, but they usually stay out of the TECH.
You can also send a PM to anyone if you are feeling unsure.