Did you find out what was behind ? Decent joists in a stud wall should be well up to the job, maybe requiring a little strengthening. Unless you use very good fixings in the brick wall, I'd sooner have 2" screws in wood than a dodgy wall plug in a brick that's not completely filled with concrete

Mine's fitted onto 2" studs that are attached to a breeze block wall and hasn't shown any signs of movement yet. I also have 12mm MDF boards to give the whole thing more strength though. (Build pics here http://slideshows.scullard.com/plasma/)

Benefit though would be that running cables is a doddle in a stud wall compared to bricks