shark eggs and more

Hi all , just want to check I'm not being daft , after moving house and getting the local shop to rehome my fish , I've now started new tank over last few months and purchased a couple of shark eggs then a couple weeks later a zebra eel that I've just managed to get to feed (taken a couple of weeks of reading to get ideas lol) but I'm considering purchasing a small stingray to Finnish off the tank.

have i gone mad or is this a good combo ? also my tanks only 4ft long at min plan to upgrade as the fish require so size dosnt matter in this case

any input is great full

thanks