I have not seen dimensions for either motor.
Might have to spend ~$300 for a used motor to get started.
My 2018 XT250 was only about 10 MPH faster than my 2017 TW200.
A twin may be an improvement.
My 1967 CB160 Honda would run an indicated 92 MPH (speedometer error not checked, but strongly suspect).
OTOH, my 1967 CL160 (used, purchased in 1969) would barely do ~80.