Supersquid girl. What kind of experience do you have with salt water/cephalopods? I got a big (8 foot) diameter circular tank when I was working with cuttlefish in Hawaii. Mine was an aquaculture tank.
My advice is to get saltwater experience BEFORE you tackle cephalopods! They are difficult to maintain and are supersensitive to water quality, food quality and just about anything else and you're picking one of THE most difficult cephs to hold. Most squid are hard even for institutions to hold and require LOTS of money, equipments, space, time, ...................................!
Generally most people find octopus a bit easier BUT I can't emphasise enough that you really should get some saltwater aquarium experience before taking on a cephalopod pet! Saltwater aquariums can be trickier than freshwater to maintain, you need experience in balancing Ph, salinity, nitrate/nitrite/ammonia cycles etc, etc These are super important. Most marine species have a very low tolerance for variations in these factors and cephs are especially sensitive.
Above all else do heaps of research! There are many great articles on this in the ceph care forums.