McFarlane cables
I really recommend buying McFarlane cables rather than the green-sheathed cables that Vans sells. Vans cables seem to last around 500 hrs if near any heat source, even with heat shielding, firesleeve, foil wrapping, etc. They get sticky inside when subjected to moderate heat.
The McFarlane cables are about 3x the cost, but worth every penny when you think about how difficult and frustrating it is to change out one of those cables on the RV-8. The access and install on an RV-7 or RV-9 may be enough easier that the economics would suggest just replacing the green cable every 500 hrs, but on the -8, you really would rather not ever do it, and the silky-smooth, last-forever McFarlane cable is the way to go.
Of course, since they are custom-ordered, you should be darn sure of the length first before ordering one. And you can specify the cable travel to be a little longer than the std Vans cable too, so you don't have to fine-tune the quadrant adjustments so much to get full travel on throttle or mixture.