LionFish says......
Good to see someone that likes a good challenge. And glad to see someone has an interest in Archers. Well, first off, the 2 triggers will work but of course, we're talking about 2 fish that get to be nearly 10 inches after a period of time and they can do serious damage to other fish. I usually recommend that people keep one trigger per aggressive tank, or get all triggers. It seems to work the best that way. However there are excpetions like there are to all aquarium matters but seeing as you do like a good challenge, I would recommend you try an Angler. I sure would like to but I can't find any and my tanks are already full. Now, as you probably already realise, they can wolf down quite a bit of food. So if you decide to get one. Make sure it is small enough so that it won't be able to eat the fish but still big enough to defend itself. I think buying a 2 to 3 inch Angler would be alright after the rest of the fish were at least 5 inches long.
Next, I got my Archerfish and the catfish from my LFS who deals with a lot of rare freshwater fish. I recommend Archers to everybody but you have to have great water quality, perfect salinity, and a good food supply. Mine eat at least 10 pellets a day each, or they get 10 dozen guppies a week. My main mistake was not buying a cover for the very back of the tank. They spit a hole through my dry wall but they have hit flies on the wall before. They can hit people across the room too. They are one of my favorite fish of all time. The catfish has been trickier than most fish I deal with. It has been a bother to my Knife fish as the knife is releases small electric shocks to stun fish and locate fish. I believe I mentioned I had a ctafish rather than an eel, but I may be mistaken. I will go back and check the post. I have had an electric eel in the past but he climbed out of the tank. My fault. But they are neat to watch, too.