Just so we all know what we're talking about, some terminology. The March pumps happen to be magnetically coupled to the motors, which avoids the need tor a seal to keep the liquid out of the motor, but this says nothing about the pump head itself. The Marches and most other common small pumps are centrifugal. These will not self-prime, meaning they need to be below whatever you're pumping and filled with water or they will just sit there and spin--which is usually not too good for them.
In theory, you could magnetically couple the peristaltic pumps, but it doesn't get you anything. The liquid being pumped stays in the tubing and so there are no seals required. They are used in things like heart-lung machines because the inside of a piece of tubing can be made a very sterile place. So, they are good for transferring beer. I have one of the little Cole-Parmer Masterflex pumps that uses hose about 1/4" ID, and it transfers 5 gallons in about 10 minutes or so--acceptable. This is a little too slow for some of my other tasks in a 15-gallon brewery. You do need to use specially engineered tubing, and it isn't cheap. I think I had to buy about $50 worth to be able to use a $15 pump ($500 retail--now how much would you pay?).
There is one additional common small pump, a gear type pump. This works like the oil pump in your car and uses a pair (or three) small gears, and are positive displacement, meaning they will suck a vacuum and are self-priming. They don't like chunks in them, as the small gears mate fairly closely, but I've never had a problem from that. Most of the small ones are magnetically coupled like the small centrifugal ones. Also, stainless heads and they seem to have no trouble with very hot liquids and don't cavitate like centrifugal pumps can with liquids near boiling. Micropump (especially) and Tuthill are the brands to seek out. I like these for most brewery tasks.