Hehe, I have a fish/sea turtle tattoo in the way too. I already made an appointment with a reputable tattoo artist, and remember to find one too. Ask around. Research. A good tattoo ain't cheap and a cheap tattoo ain't good.
BUT, my suggestions is to bring actual photographs of the fish you want tattooed on you rather than a drawing or other tattoo pictures just because it'll be more accurate. If the tattoo artist can't draw that out then it's time to find another one. If you're thinking of another fish koi are a very popular choice, and they signify overcoming problems... a koi swimming upwards means that you're still trying to overcome problems, and a koi swimming downwards represents the problems that you already have. They're very popular so it's probably a safer way to go but don't get it because you think it might be easier... get it because you looove it