You don't need to add weight to the bars. I was having a front end wobble at the time (turned out to be a cupped front tire) and added the MS bar end weights in an effort to correct that. The MS bar end weights did not fix the wobble of course, but they were chrome (+), and they gave me a bit more hand room. I can move my hands down over the end weights and let the friction of the area between my thumb and first finger against the throttle act as a throttle lock when cruising. It probably sounds dumb, but trust me,

, it works.
If you do want to add weight for some reason, I can tell you that a Bar Snake won't work. Some guys fill the bars with lead shot. You will have to plug any holes in the bars first to do this... said Mr. Obvious...
If you shoot shotguns and reload your own shells - no problem.
If not, there is info on the web about what size shot to buy and you may find it's only sold in 20-25 lb bags, etc. etc.
For me the bar end weights are a more sensible solution.
As far as the reservoir position, a lot depends on how the bars fit you when you're sitting in the seat. You don't want to ride with your wrists cocked at some weird angle, so you have to position the bars accordingly.
That will determine where your reservoir ends up on the bars.
The above info is based on what
I ran into when installing Buckhorns - your results may vary.