why not get a leftover for cheap and the money you save will more than cover suspension work.
racetech springs for front and rear are about $300-400 at most which is a hell of a lot less than $1500
or you could do an R6 fork swap for around $400 plus another $100-150 for a rear shock. and then they would be adjustable.
on the other hand i feel that if i bought the FZ8 which uses an almost identical frame to the FZ1, that i would wish i had that extra power and that sweet 5-valve Genesis motor. and if suspension matters, the 1 has that covered too. also a naked conversion is cheaper than a faired conversion, if you dont like the set-up you start with.
The only reason that i might buy the FZ8 would be for gas mileage. where the FZ1 only gets around 35-40ish i would imagine the 8 does better.
This Turkey, don't jive.
09 Yamaha FZ6 in Faster Blue