i got the longest cables that mountain performance sells. then i went to the local race car shop and used stainless steel braided line to make a brake line and used 3/8 banjo fitting that adapted to the fittings on the brake line. depending how high you go the cables will probably go over the air box when done, i didnt like that so i also added cable extenders that are for the four stroke cableb and made them fit.
I dont think that 8in longer cables will work cause ive got 4in taller handlebars a 4in riser and the pivot adapter witch should be around 10in or more. Im wondering if the powermadd cable extenders will work but it dose not include the yamaha mm on the fittment chart so I dont know but attak06 said he used the ones for the fourstroke yamahas so im not sure what I need.
I put a 5" riser on my MM700. I used the throttle cable off a viper and just bent the 90 degree bend in the metal housing straight to give an extra 3 inches of an already longer cable. For the brake line I just used power madds extention. The whole set up including risers only cost about $130. I would stay away from fly risers (imo) they tend to slip on the adapter you would have to use to run them. The stock wiring will go 5" with some re-routing.
I have a powermadd 6 inch rider with the pivit adapter and the 1-1/8 bar mounts, then a set of pro taper CR double high bend moto bars. Works excellent
Its about 8 inches of rise to the bars, then about 1-2 from there and then extra width