Need some help and know how on a small studio design

I have a building which is 20' X 16' with 8' ceilings. The external walls and roof have been finished. Inside NO work has been done, only studded walls. Because of this I don't figure I will need to post a pic. I am located in southeast Tennessee (USA) and don't have any neighbors in considerable distance. There is a highway overpass about 200 yards away and a traintrack about a quarter mile away that is considerably loud with low end rumble. My main concern is to have 3 rooms. A control room a live room/booth and a bathroom. And when I say bathroom I mean bare minimum. Just enough to do your business and and still be able to squeeze your way out LOL . I don't really have any ideas set in stone for the inside which is why I need some help. Not paying mind to standing waves I originally planned on splitting the distance in half and making the studio room 10' X 16 ' which goes along with the cottage recording studio plans on the net and using the other half for control room and a bathroom with a small hallway separating the two to also serve as a trap. Unfortunately that won't leave me with much of a control room (like 10' x 7' or something) I am really unsure about that. I plan on doing recording as a business to the public and really would like the space in the studio to accomadate a band if needed. In the past I mostly recorded lots of rap and pop artist and didn't need that much space for a studio but would like to be able to accomadate bands so I can expand my business. Any help or insight will be greatly appreciated. Thx :D

Aloha Res, How about these for some ideas? Aloha 8)

Thx Kendale those are some really awesome designs. :D

Aloha Res, We can both thank John, as I believe they were done by him. Aloha 8)