Wow! That's the first titanium cylinder I've seen. Great looking grips.
S&W used to sell titanium cylinders through their parts department, but ceased doing so several years ago. This one came from a seller on eBay that had a spare NOS cylinder left over from a 386 that he previously owned.
The grips are Hogue Pau Ferro conversion grips with a stripe cap. By far my favorite wood grip for these guns. Ahrends retro targets are also great, but just a tad too skinny for a full lug S&W IMO. I also purchased a couple sets of VZ tactical diamond conversion grips during their Black Friday sale and they are quite nice as well...albeit with a much different grip angle.
If you are planning to purchase a set of grips and need photos of the Ahrends or VZ's, just let me know. I also have a spare set of Hogue Jerry Miculek K/L grips if you are in need of them.