Lynden
a "fish hater"
I agree with you on this point, but you must realize that buying a ten foot tank is easier said than done, and we get TONS of people on here who "thought they would" be able to get a huge tank on a dime. If you can truly get this huge tank when the time comes, buy whatever you want. If there is even a hint of uncertainty, stick with smaller fish. There are plenty of aggressive or predatory fish that can be kept in a smaller tank for even their entire lives, and you can buy the biggest fish if you get the new tank.There is absolutely no need to have a 6,7,8ft tank for juvenile fish
Also, a few large tetraodonts (undulate/clown triggers especially) that seem frustratingly adept at de-finning and de-eyeing lionfish. Perhaps a lionfish and a small group of batfish or heniochus, plus your green spot puffers, would be better for this tank. Choose wisely, 'cause it will suck if in the future you have to part with one or more of them.