I was in this same position about a month ago. I knew I wanted a single pump, but wasn't sure what way to go. I looked at both mid-high end diaphragm pumps as well as linear piston pumps. In the end, I went with a diaphragm pump (DAPMH20) and it has been great. Very low noise, and plenty of air. I talked to the place that I ordered it from, and they were very helpful on helping me size the right pump. Since I run Hamburg filters, we went a little bigger.
The other thing that I did that worked well for me was to run 3/4" pvc pipe around the room in a loop, and then tapped the outlets off of the PVC pipe. This was really easy to do, and I only used friction fit (no gluing required) and it has been working just fine. I ended up getting the pump, tap set, tubing, adjustable flow outlets all from the same place, and couldn't be happier.
If you think that you will continue to add more and more tanks, you might look hard at the linear piston pumps. They are amazing, and super quiet. For me, I did the math, and even maxing out my existing space, I wouldn't outgrow the DAPMH20 pump, so that is the way I went.