pistons actually look fairly normal for those miles, what does the cylinder look like.
That price for a rebuilt crank is pretty good. Just make sure the tack weld it up after pressing together so it will stay put. for all that work, I'd get the crank rebuilt vs used. At least you'll know EXACTLY what you have. Stator should be easy to source.
You could always buy a used motor/bike and have all the spare parts you need. Chances are you'd only need a top end job then. Just a thought.
Don't scrimp on that bottom end though, and make sure you have a reputable shop do the bore job. Personally I'd stick with stock pistons and go with the recommended clearances vs Wiseco forged with larger clearances. Wisecos will rattle more and unless you plan on racing, the stockers will work just fine. Do a good job of testing your autoluber just to make sure it's working, then properly bleed it when you get it back together. Run synthetic 2 stroke oil.
I just got my little Suzy T250 going last year. Didn't need near as much as yours but sure is a fun little ride. Will cruise at 60mph all day long as it's not even on the pipe yet at that speed.
2006 HD Sporty 1200C, 2006 Triumph Scrambler, 2001 Ducati M900, 2001 Honda XR650L, 1994 HD Heritage, 1978 Honda CB750K / sidecar, 1977 Moto Guzzi 850 LeMans, 1976 Honda CB750K, 1965 Honda 305 Dream, 1973 Norton 850 Commando, 1971 Triumph Trophy 650, 1970 Honda Trail 90, 1970 Triumph Tiger 650, 1973 Honda Z50, 1984 Yamaha Virago 1000, 1981 Honda Passport 70, 1970 Suzuki T250, 1971 Yamaha RT1 360