With the Rivco risers alone and
stock bars, +3 inches is
WAY too much on throttle cables at least. You want
maybe 0.5 inches over the stock, otherwise they start bulging. I got +1 inch and had to route them through the left hole on the triple tree to keep them off the shield. The throttle cables are laid in a gentle curve as it is, and you can in fact make do with the stock cables for the Rivco risers. Just need a
touch more length to really make them perfect.
I got Barnett's cables. The clutch cable is probably fine with +2, +2.5, but
make sure you measure your current ones very thoroughly and order a specific length from them. I'd recommend you get the bars you want, mock them up and measure how much your stock cables are off and only then order, otherwise there is a big risk you'll be unhappy.
For me, the lengths I got the first time by ordering "Rocket 3 Touring stock length + 2 inches" were wildly off. Comparing their design schematics (they sent me a set in PDF) with my stock cables showed pretty noticeable discrepancies to begin with, and they also managed to make the throttle cables inverted - ie, the longer one was hugely shorter. They did make good for free though, I got a complete replacement set, so in that sense there's no risk ordering from Barnett. Their low friction clutch cable really made a difference too, so I'd recommend them. But you have to pay attention to what you order, and compare to your stock cables and give a specific length you want for each cable.
It's surprising how exact you have to be for one like me who hasn't really replaced cables before. Cables are stiff and have zero give, so just one inch off means they bulge out and up like nobody's business. They also have to be in a smooth curve, any attempts at kinks, even slight kinks, will cause them to bind (which I'm sure most people reading this know, but I just didn't allow for how precise you had to be at first.)
As for brake lines, Spiegler and HEL have nice ones. The primary difference for the R3 Touring to the Rocket sets they have (that won't fit out of the box) is that the line from the reservoir down to where the split occurs is longer, so you need to order a custom set. Again, I'd recommend measuring and mocking up before placing an order.
If you want to clean up the electrical wiring too and get it all shiny:
http://www.techflex.com/prod_cxn.asp
