Better low volume circulator recommendation?

Jolly Bodger

I'm building an Infloor system with small zones. 2-4 loops each all below 250ft. Each one will have a circulator and it's own 3-way mixing valve. The idea is to let the circulators run constantly and feather the temp with the mixing valve.
Since i'm going to be running the pumps all the time I want efficient pumps. And they only need to move 1-2 GPM. My inital thought is UP15-58 on low speed. It is fairly efficient and cost effective.
But is there something else I should consider?
Check my math here. If the UP15-58 is restricted to 2 GPM by the radiant manifold it should be drawing less than it rated amperage because AMP draw is directly related to work done. And head pressure does not mean as much as GPM of flow?

Rich_49

http://www.tacocomfort.com/products/variable_speed_products/viridian_vr1816/index.html

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/59896341-submittal.pdf