340 Rod questions

You can buy single ring sets. You could try to scratch the cylinder with 240 wet or dri.. since the motor is coming back out.

Any ridge in the cylinders?

My thought on the bearings is that I would probably put in the cheapest new set I could find for now, since the motor is coming back out. Or even just re-use what you have, depending how much you plan to drive the car 'til the rebuild......? BTW, Kings are mostly AL and so are usually harder.