Welcome to the Stovebolt Rick57
One thing I can say about stainless bolts is that they can work loose real easy as the hardness of the stainless does not allow the metals to grip each other as plain steel would.
You would need to either use some good loc-tite when assembling the stainless nuts and bolts or use some type of self-locking nuts with the stainless bolts.
As for painting them,,,, why not polish them
