That valve is not ideal. The chrome will wear off in time, and expose the base metals. It's not food grade. That said, I have the same, or similar valves. I've used them for many years without any bad beer that can be attributed to them. I would feel fine about using them. As for the weldless kits and washers, many homebrew shops sell them. An internet search will reveal more retailers than you'll know what to do with. But if it's going through stainless, I'd invest in having a stainless fitting welded by a shop. Less headaches and lower cost in the long run.