Looking for a donor bike for an EV conversion. Since I won't be using the motor, I'm not sure what I need to look for frame wise, suspension, and wheel wise. Are 250 frames smaller than higher displacement motor bikes? 750/900?

What I'm looking for:

$1000 budget

Lightweight

Chain Driven

Upright Style (Not crotch rocket or Harley style cruisers)

I don't know if what I'm looking at will handle like a boat when I'm done. I want something nimble.

I'm looking at:

Honda XR650L

Honda CB750s 80s

Suzuki GN 80s

Other suggestions?