I have a 2011 Roadster. I have considered a Touring Bike for the past two years.
This my 2009. I have made one or two tiny changes (I no longer run a car tyre) since but........
You must get the seat to feet positioning correct for you. This depends on your physique. The Roadster (post 2010) pegs are a nice neutral position imo. If you are at the taller end of the scale than the earlier pegs may suit you better - Boards are better (imo) but there are two versions: the Classic - pictured above) and a conversion kit set which are higher and further forward. Some of the forward controls are VERY stretched out. I would not reach them.
Decide on foot position then get a seat made to put your bum in the right place.
Then sit on bike and get a set of handlebars that fit to where you want them to be. I have a Triumph seat with backrest but the seat itself is very altered inside.
Note that a change of bars will very likely mean new cables and hoses.
Suspension. DO NOT FORGET THE FORKS. Rear is very much a question of taste. If you do the forks get rears to match. Though as indicated before I would put FOURNALES on a touring ride.
Screen will be a must where it is cold and wet. I use Hand protectors - thus avoiding the need for heated grips. BUT there is a chance these will increase bar-end turbulence (depending on the bars) and can make the steering feel a bit light. Just saying.
Expect to have to do some fine tuning.
Also (imo) keep the engine tune
fairly tame near cruising speeds. I keep 5th gear a bit less zappy than 4th.