Back on topic though... as I have almost no experience with different brands of air pumps, I'd just say grab a brand name in a nice box for a decent price. Get one that will suit your tank though, as some aren't powerful enough to aerate larger tanks.
I have a tetra 10-30 with those bubble bars that use 2 suction cups to stick to the back of the tank windows. I really love it. It doesn't take up much room like those stones. I actually cut mine with a hacksaw and replaced the caps to customize it to my tank. I think they are made of plastic. At first I bought a big one that covered the entire back of my tank window but found that it made my power filter gasp for water so had to cut it down.