Ever the cheapskate, a set of used plus 40's are worth a go in the damaged block bored to suit. Even cheaper, a set of used plus 30's.
All depends on how bad the damage is and how fastidious you are. The major castings are the parts they don't make in any economic volume and we should preserve them if we can. A set of used plus 30's in the existing bores give a cheap runner, which although possibly a little smoker gets a bike back into use. If it smokes, you know the reason why and don't have to worry.. When it smokes for no good reason, then you get the sleepless nights!
The alternative is a relatively big investment at current price levels for quality pistons and rings which may never be fully enjoyed depending on current use.
Swarfy.