I have rode several sleeved bikes.
I always warm them up very gently, I have them jetted correctly, and run a quality 40:1 mix.
They will usually last a good long time.
Yes, I would rather get one chromed.
In your case you need to know how bad the damage to your cylinder is.
If it is normal galling then chances are you could go 1 size over and be fine.
If it has scoring or pitting then you have to know what size it will be after the damage has been machined out.
Many shops will not even bore your cylinder unless they have the piston you are going to run in it so that they can be sure to bore it to the correct size.
If your going to have it bored locally I would take it in with a list of oversized pistons that are available and ask them what size to get.
I'm sure they will be happy to help you.