While I don’t really see any “kits”, there are a number of barrels currently on Gunbroker, starting around $460. Add a couple factory mags and that’s everything that comes in a conversion kit anyway.
I don't concern myself with the finishes too much. Almost all of my barrels were discontinued at clearance prices. Except for the Ti 50AE, I did that on purpose but it was still pretty cheap in comparison to the blued/black ones available at the time. It's crazy how messed up the market is for these things right now.