Hello everyone! I’ve recently gotten a 75g, and was hoping to get a couple of goldfish for it.

Ideally, I’d like to have about 5 goldfish, and my s/o has her heart set on having a comet goldfish. I’m a bit more versatile with my options.

So my questions are:
1. What kind of goldfish could I get that would fit comfortably in a 75g?
2.If I got a comet, would I still be able to get 5 goldfish?
3. If not, how many other goldfish could I get and what kind would they be?

I know these questions are a bit vague, but thank you in advance if you’re able to help!