Look on eBay for a cylinder that has all the valves still in it.
Take what you need and sell the rest.
All 2T's are getting harder and harder to find parts for.
10 years ago I could buy a 98 125 for less then 500 dollars.
Now the same bike with a blown motor is 700-1200 in our local area.
And, they don't come up very often anymore.
Until the economy takes a serious turn up, younger riders won't have expendable cash to buy new bikes...
I'm waiting for the glory days again