looks lovely, congrats on the nice set up.
only advise I could offer, no discourtesy intended as you may already know this, however with the ropefish, ensure all openings in the hood are sealed as they are great escape artists! in respect the clown knife, I had one and it was massive, ended up having to get rid unfortunately. then again, I only had a 4ft tank back then, if you get a 6ft tank I am sure you will be fine. One other thing, and I am not sure if you have sliders on your tank, but the knife will splash with his/her tail when it gets to a certain size, when mine did this, it wrecked the unit under the tank.
Mine used to love blood worms and lancefish.