I can relate to your issues. I absolutely hate sitting straight up or reclining onto my tailbone, its uncomfortable and just feels awkward. There is a really simple solution, and you don't need rear-sets to do it.
Not sure how tall you are, that will matter, but if you throw these bars on it forces you forward just enough that you aren't sitting on your tailbone, 2-3 inches forward of stock and 2 ish inches lower than stock. At full arm extension, I am "just" ahead of that position where my whole weight is on the tailbone. I rarely ride like that and usually lean forward in a sort of half committed sport-bike position. The real reason I finally did the switch was the angle the stock bars puts your hands at when you are leaning off the side of the bike in a sharp turn, I found it puts the inside hand at a strange angle to make adjustments. These gave me a slightly forward position from stock and flatten out the angle of your hands enough to feel "correct" to a sport bike rider. They do not hit the tank and don't pinch the hands at full lock against it.
At $50.00 it's also really hard to beat!
Exhaust - Do whatever you like the look of. Finding a shorty setup for a roadster is not going to be easy.
Rearsets - You could make an adapter plate to move the stock controls further back and slightly up. Would take a drill and way to cut steel neatly, just cut the mounting plate, drill a couple of holes in whats left attached to the bar. Use a plate lined up to match the new mounting holes on the bar and the control and move them where you want. Powder coat to finish it off.
http://www.dimecitycycles.com/1-inch-gloss-black-dcc-original-classic-handlebars.html[ATTACH=full]22658[/ATTACH]