"orangetrader" wrote:

I can use toggle bolts but I don't think the drywall will have enough
strength. I thought about cutting two pieces of wood and mount it
horizontally into the studs above and below, and then screw two vertical
pieces to them to form a frame, but this will not be symmetrical.

Close,

Cut a piece of plywood, the size of the unit or bigger as needed.
Install where you want it. Strongly secure where the ply happens to
cross the studs. Secure the unit to the plywood.

Depending on the problem your trying to solve, anything from 1/4" up to
13 ply 3/4" Baltic Birch plywood can be used, a nice plywood could be
stained and finished.