Choosing a beer pump
This was one of the more easy decisions. A pump is a MUST for any 1/2 barrel brewery.
What to look for in a pump;
1 – Rated high temperature >200deg F.
2 – Polysulfone head housing
The March High Temp Brewing Pump
Model: H315HF
Price: $150
morebeer.com
This is pretty much THE homebrewer 1/2 barrel pump. Here is the pump on my current system using 1/1.5 inch sanitary fittings.
H315HF – Notice the clear plastic protective cover. I have found this to be very important for boilovers and other mishaps.
You will note that the pump location on the current design is just about even with the bottom left keg. In some instances we have to inject water in to prime the pump. Most of the time it works fine. It’s a tradeoff we made for the current system.
Below is the pump on the first version of the half barrel brewery
Plumbing the Pump
Ideally, plan your brewery so the pump is several inches BELOW your very bottom keg. This will make for easy priming. I have never ran into a problem where I couldn’t prime.
Other considerations
Other things you will want to do is to install a switch (not on the stand, but away from any water spillage) that the plump plugs into. This is so you can easily turn the pump on and off without needing to unplug it constantly
HalfBarrelBrewer 
How hard are these to clean/sanitize? Can you do strike/sparge as well as wort with one pump, or is two pumps required?
With the hard plumbing on the brew system, the pump gets sanitized when I sanitize the system the day before. I just recirculate between the kettles with PBW. With the exact configuration I have, only one pump is needed as the boil kettle gravity sparges the water and the hot licqour tank at the very bottom collects the gravity drained wort from the mash-tun. Once all the sparge water is in from the boil kettle, I pump up the collected wort to the boil kettle. If you have a 2-tier or one row system, you may need two.