Get proper brakelines and a NICE mastercylinder...

e.g. Suzuki GSX600F, that way you have a micro-switch for the brake light, that will not play up and have proper brakelines. From there onwards, I would tear the calipers apart overhaul them with new seals and pistons (if necessary) and then get sintered EBC pads.

I still run the original calipers on my RatZ (Z1000J) and they are more than satisfactory (the only thing at all is a certain spongyness in them, when used really hard e.g. on the racetrack)

The thing with the Tokico-six-pots is, that there are no piston sets for them AND they tend to lock up even modern 120/70-17 rubber, if used too hard.

Don't worry about the wheel btw. a spoke wheel is way more flexible then a cast wheel.

Hope this helps
Greg