sorry mate, can't offer any insight on the above, other than a CB250RS being widely regarded as a belter...
but what about an SRX 400? They're brilliant little bikes, very pretty, great handling, and a good motor. The 400 (Actually 398cc) has cheap tax & insurance, not much different power to the 600, and can sound great. Electric start post-1990.
Downsides are as per most bikes of the era:
-rusty tanks
-20 year old electrics
-generally a bit scruffy!
-suspension will probably need sorting if you want the "great handling" I referred to!
-top ends can be a bit fragile maybe
-exhausts are now hard to come by
-ridiculous and complicated twin carb set up.
But I have quite a soft spot for them...
happy hunting!
a