Thank you, John and knightfly!
I like John's layout. but...hmmm. now I'm gonna look stupid, bu I'll say it. I know that your plan is MUCH better then one I suggested. Problem is... I know it will sound good and that my mixes would be easier if the layout is like John sugested (thanks again!).
But, sometimes I work in radio studio that is something about 3 mx3 m, plus small vocal booth about 1.8 m x 1.7 m. It's small studio. It's bad considering it have same dimensions of paralel walls which may result with standing waves. It have not some special gear (computer, mix desk, CD and MD player, vocal compressor). But, I can compensate that with my ears, and commercials I worked in that small studio sound ok. Costumers were satisfied. And that's were the problem is. COSTUMERS. When I record and produce commercials in that small studio, and costumer come in it, they want to hear speaker reading text. And that's why I want to have iso booth if possible. And cosutumer don't realise studio's bad acoustics (ok, it's not so bad, but it could be much better). All they see is walls coverd with studio foam (I'm not sure how it's called on english? Wavy foam that treat mids and highs) and glass between voice booth and studio. And when they see foam, they're happy. They saw that on TV and they think that's professional. Their comments are something like: oooh, it nice. Foam...mmm. It's real studio!
So, I want to build at home something like that, something that will look as costumers expect to look like. I want to "play" psychological and make them feel comfortable, pleasent for their eyes.
I'm not sure if you unerstud what I'm talking about. Maybe it's hole new theme for debate, relationship between costumer and studio engineers.
I'm working for paying my bills, so I would prefer that costumers feel happy and order commercials from me. Acoustics I can work out with acoustical treatment and compensate with my ears (I'm expirienced, I could mix commercials in my living room and it would be good enough-it's not music).
Please, don't get me wrong! Maybe I'm a little bit fuzzy

I hope you can understand what I'm talking about. I'l try to place vocal booth somewhere in John's plan. It's good, I like it! Maybe to rotate something or I don't know, I'l try to figure it out. If I can't place vocal booth somewhere, then it'll be John's plan without booth.
Any comments are appriciated. Thank for your effort verry much!