The Rocket III Touring may suit you since it is similar to a Road King, but a bunch more power. It's also better suited for hauling a passenger, similar to the Road King.
For reliability, I have an early 2005 (July 2004) Rocket III Standard with 65,500+ miles on it. The biggest issue with the bike I've had is the throttle position sensor, but I believe the last one I had put on is a new 'improved' version. Mechanically, the bike has been great. I've traveled from here near San Antonio up to Sturgis, across Wyoming, Arkansas, Oklahoma, Louisiana, etc.. and have never been stranded. I wouldn't hesitate right now to jump on it and go cross country some where.. ( I so wish I could! ).
Aftermarket - There is a better aftermarket for our bikes than you think. Not as much as some of the others, but try newr3.com and flipmeisters.com for a few ideas.
Handlebars - are standard 1" handlebars, so any other 1" bar will go on. Cables are pretty standard fare as well. For the Roadster, Rivco makes risers that are 1" taller and 2" back and use standard cables. The touring has more riser options since the gauges are on the tank.
Fender Badge - The badge on the front fender of the Roadster is screwed on from behind. I had to fill in holes when I had mine painted.
TORs - are Triumph's "Off-Road" accessory mufflers. They give you a little more sound, and a little more power. D&D, and several others make slip-on mufflers, Jardine makes a replacement exhaust system (seen on my bike in my profile pic). With Jardines and a Power Commander, I was just dyno'ed at 139 HP and 142 lbs/ft of torque.
K&N filters - The triple K&N filters are available as a kit from flipmeisters.com. The stock air box assembly is a pain to remove, but putting the K&N filters on is a piece of cake. You will need a PowerCommander or TuneBoy/TuneECU software to modify your fuel map as well, since you will be supplying the engine with more air. I have not done this mod yet, but it is good for another 15 HP or so, combined with a freer flowing exhaust.
Vibration - I've ridden the R3 everywhere and have not had a problem with vibration.
Seats - I settled on the seat from the Triumph Rocket III Classic for my seat. I don't have any experience with the new Roadster seat or the Touring seat though.
PC-V - I HIGHLY doubt it. I know the PC-III plugs into the Rocket's wiring harned between the ECU and fuel injectors. I doubt the connection is the same as the Raider's.
Rear Fenders - There are no aftermarket rear fenders, though many have cut their's down. I have often thought of getting a flip-up 240 size rear fender for a Harley Custom (similar to Softtail Standard rear fender) for my bike and modifying it to fit, but there are no ready-made options.
Wheels - The only aftermarket wheels I've seen are carbon fiber wheels from Blackstone Tek. They are incredibly expensive.
Headlights - There are several who have swapped to a single head light, but WHY? That's what makes the Rocket III! (Sorry Touring guys!) The Rocket III Touring already comes with a single head light.