I would look for as late an 1150RS as I could get. Preferably one which had the ABS removed. (Servo abs was a liability.) The older bikes may suffer from some degree of electrical gremlins as the wiring ages. The most common being the hall effect sensor.
I loved my 1100RS and only sold it because the riding position became a bit too sporty for my back. Some addressed that by fitting flat bars instead of the low ones. These were also rubber mounted and became spongy and vague after a while.
Other issues? I would look carefully at the exhaust fittings in the cylinder head. The nuts rust and can be a bugger to replace.
Great bikes though and well cared for, low miles are surprisingly common.
Like
this one for example. I could be tempted! It's got ABS2 which was far more reliable than the dreaded servo abs.
Or this one? High miles but appears to have been very well cared for.