Go with Aquaclear but make sure you buy it from some place with a good return policy. My AC50 is silent but my AC110 was noisy (motor noise). Just keep exchanging them until you get a silent one.
If you do get an Aquaclear you'll want to either strap the lid down so it doesn't rattle or put a dab of silicone on each corner. That's the other big source of noise.