The generic "blue lobster" is usually Procambarus alleni, which is a highly aggressive species of crayfish. You'd be best just getting a smaller tank and housing it by itself or doing a larger species only tank (but with only a few crayfish).
Are you picking them out from a LFS or the internet? If you're going to do the latter, you can find a variety of crayfish to suit a better range of tanks than if you're just picking from what a LFS usually orders in.
That aside though, check out some of our stickies for care information on a few different crayfish species, you may find something interesting you like to keep more. And keep in mind, with a few exceptions, planted tanks are going to get ripped apart, most tankmates may be viewed as a food source and crayfish usually aren't social (so if keeping multiples, use larger tanks).
Personally, I'd recommend picking up a Red Claw... they're beautiful, large, more docile in temperament, etc. And very easy to care for.
