It is not too difficult to get the cylinder re-blasted.
I sent one back to S&W (after removing it from the frame) a couple of years ago and they re-beaded it for a reasonable cost.
As for the powder rings on the front of cylinders, I have good luck getting them off with a bronze brush (looks like a large toothbrush) from Lowe's (cost about $3) and BreakFree. The bronze brush generally does not mark stainless steel.
Scotchbrite pads come in several levels of coarseness; the green should not be used on stainless guns -- it was meant for scrubbing floors.
Green - Coarse (available in Wal-Mart)
Gray - Medium (available in NAPA Autoparts)
White - Fine (available in NAPA Autoparts)
I used gray then white, followed by persistent rubbing with Flitz Polish (a tube is around $8 on Amazon and lasts forever) to recover some scratches on a stainless Model 60. There is danger in over-polishing and making it too shiny, and you definitely want to avoid using a power tool to do any buffing! And you have to be careful not to smooth out the markings or edges. This applies to a regular stainless gun, not one that has been bead-blasted. The regular stainless has a sort of "grain" to it that apparently comes from tumbling the gun during finishing at the factory. It is hard to get that back after over-polishing, but my Model 60 looks very good now -- much better than it did before. (The cylinder and barrel have "grain" lines that are more linear and can often be brought back to looking good by using the lighter scotchbrite pads, gray or white, lightly in one direction).
Back to bead-blasting: I'd send it out, probably to S&W, if I could not find a good (probably cheaper) local expert.