gaskets can be made if you have the skill.. material is available at auto parts stores.. If you are gonna open the gearbox (if it has one) those larger, thinner gaskets are a little more difficult to cut.. And one thing to keep in mind is gearbox gasket thicknesses are important since gear/shaft/engine case clearances are probably involved.
I never heard the term pushplate before. Belts are belts if the width and length is the close to the same.. new clutches might be difficult to find, depending.
Do you have a manual for this bike yet?