yamaha kit is a bit of a waste of time and money in my opinion.
about the only thing good about it is the widened triple clamps, which im not too sure your speedo is going to be compatible with. however it should prevent you having to hack your fork guards to make your brake rotor/120 front tire fit.
I think the best method would be grabbing an aftermarket wheel set second hand or new with the rim sizes you want, along with the brake set up you want. Theres pleanty of second hand yamaha stuff being sold at any moment on forums or ebay.
Then for speedo go for the trailtech vapor.
There is also the option of using this mob
It really is up to u