The addition of a power head would be my suggestion. You can place it where you need additional water movement in your tank. Downside is that you have to look at it inside your tank.
I have 2 Seio pumps in my tank (one 820 and one 1500) and have been able to place them in areas that the rock work hides them but does not impede there flow. My rock work is not placed against the back of the tank, there is about 6-8" of space between the back glass and the rocks.
The Seio's are nice because they produce a high volume, wide path of current. Most of your large power heads produce current that is so concentrated into one small area that it makes it hard to put anything in front of the stream.
Or if you have the cash you could go with Tunze pumps, the Cadillac of water movement.