I've put a number of the mods you've mentioned on my '07 M50 Limited Edition. I've attached thumbnails showing the OEM windshield, a set of Memphis Fats clear lowers, Jardine Universal tilt passenger's backrest, Jardine rack, Grasshopper driver's backrest, Lindby highway bars, and Saddleman Cruis'n Slant Bags - Jumbo.
Regarding the utility of the OEM windshield, my experience is similar to what was related in an earlier posting. I really like the look of the windshield on the bike and it does a great job stopping the wind from hitting you in the chest, but does nothing for your helmet. To remedy the head buffeting I put on the set of lowers and that solved the problem. With the mounting brackets they cost less than $100 and are well worth it if you are having any helmet buffeting issues. They come in eight different colors, I think.