ceviche/ceviche quality fish in Baltimore

I am craving ceviche for dinner tonight, one of those cravings that isn't going away unless I satisfy it. I have a lot to do tonight, so I'd rather make it at home, but I've never made any kind of raw/semi-cooked fish preparations at home and I'm a little nervous and I want to make sure I pick up the best seafood I can. So where would you go to get the FRESHEST, HIGHEST QUALITY fish possible in downtown Baltimore? ( I work in Federal Hill, live in Mt. Vernon, REALLY have no desire to go north of the monument due to Artscape traffic.) Cross Street Market? Harbor East Whole Foods? Some place I don't even know about?

thanks!