new studio in australia

Hi all. I have attached a rough scetch of a studio plan that i am contemplating. I am planing to build a tilt up concrete building(11x10.5x4.5m) with a galvinised iron roof. As you can see from the plan i want a large tracking room and control room( where i need enough room for a 3m mixing desk) 2 booths(one for vocals etc. and one only needs to be a small amp room) and an entrance,kitchen,chillout room(one room). 1-What do you think of the plan? 2-Do you think it can be done better? 3-Should i have 3 phase power? 4-i want one wall in the tracking room to be solid(brick etc.) 5-Do you think the hight is suficient? 6- i would like to make it bigger but due to my budget this is as big as I can go and would like to make the most of the available area. 7- can i use a mixture of plasterboard and timber for the inside walls? Thanks in advance. Anj.

any sugestions........ and what would be better for the external walls besser blocks or 4-6" tilt up concrete walls. my current space is constucted of besser and i have the most anoying resonant frequency buildups.

ok...... lets start with a clean slate, say ive got a building thats 10mx11mx4m and i want a large tracking room and control room( where i need enough room for a 3m mixing desk) 2 booths(one for vocals etc. and one only needs to be a small amp room) and an entrance,kitchen,chillout room(one room). Does anyone have any sugestions on a design for this building. I would like to do this for under AUS$100,000 and if i cant, i think i will just start again with my current 9mx6mx3m building (which im having mega problems with)