Wood or Gypsum

Hi guys! I was wondering about getting the best possible result from my Control Room... (the roof is slopped, 3m to 2,4m) I don´t need much insolation, but i would like to have a nice sounding room. Here´s the basic idea of what i wanna do with it... I would like to know if i should go with 5/8 gypsum or wood for the walls... The walls are classic solid brick walls (rendered on both sides)... Should i go with gypsum or wood to get best acoustic results? Thanks guys!

Will it be mounted AGAINST the brick, or with an air space? Steve

I think i´m not gonna use an air space because the room is small enough... So, it´s basically against the wall.