If you look at my build page you can see I made 2 aluminum manifolds also used cam tensioners from a newer virago for clearance still a pretty tight fit.
For my throttle cables I used the pull FCR cable from the throttle to the first carb and then used a cable from push side of the first carb to pull the second carburetor I had to put new ends on the cables, little tricky getting them to work together but it all worked in the end.
Here is my current jetting, both FCR's came of an 06 RMZ450 may still be slightly rich, but runs pretty damn good.
main-148
pilot-40
leak jet -70
needle-EMF (clip #3 position)
mixture screw-2 turns