The reason you can't find the Lightning grips on the Bianchi website is that they've been out of production for many years. They were manufactured for Bianchi by Pachmayr and hit the market just about the same time the police transitioned from revolvers to semiautomatics. Therefore, they didn't last too long. They were made for the Smith & Wesson round butt J and K frames and for the 1911 semiautos (didn't shroud the hammer). They were planned for the Colt Detective Specials/Agents, but I have never seen any.
I have a set that I put on my 3 inch Model 13-3 for concealed carry. Since I mostly open carry now, I'm using a thumbbreak holster that won't clear the "hump," so I've gone retro with magnas and a Tyler T-Grip. Rust under the Lightnings can be prevented by waxing the revolver where it contacts the grips. They are brown neoprene and aren't "grabby" like Hogues. The full fingergroove grip allows easy control of magnum loads.
I was considering selling mine, but doggone if I haven't just about talked myself into keeping them!
You won't find them for $25.00. The last ones I saw on eBay went for $65.00.
ECS