Barnett also has cables for the R3 and R3 Classic, in black as well as stainless braid.
You could get the 2 back, 1 up with a pair of Rivco risers, and then specify slightly longer than stock Classic cables to Barnett.
The brake lines are pretty straight when normally mounted, so there's no extra. Same goes for the cables, there is very little extra. Of course, with both cables and lines being so rigid and especially cables have to be straight or gently curved, you have to be precise or they'll bulge out all over the place.