A lot of ppl might tell you not to try this, but I think if your going to those are really good sizes for an attempt. Jars tend not to get their mean streack until around the 7-10" mark and not only are you starting the silvers larger but they also grow faster and larger, so I'd say there's def. A good chance as long as you provide enough room for all that monster. I'd also reccomend some type of dither fish. Gouramis have worked rather well for me and I've seen them in a cpl other tanks... a lot of ppl use tinfoil barbs and other types of barbs. I'd say give it a try if you have the room, just keep a close eye on the tank and be willing to split them up I'd needed.