You caught the "Midas Madness" disease too? I would recomend atleast a 75g for a Midas, and thats only for one. But, there is always room for upgrading. They are a great fish and very interactive! Mine was always so bad *ss . Good luck.
i'd go with a 120 gallon for a barred midas.
you can go with tank mates and theres a variety of options in there.
right now i have living with my barred midas :
-synspilum
-dempsey
-dollars
-pleco
-argenteas
soon to be with a pearsei
and maybe some other stuff.
you can always upgrade, and actually i'd definetly upgrade eventually.