You could use 16mm supply pipe polytube rather than hosepipe as your "water distribution main”, as it is a little more efficient at carrying water without pressure drop than garden hose.  But you may already have a lot of hose to use?

20mm supply pipe polytube is more efficient again, because it’s bigger, the water travels slower and the drop is lower.  This means you can carry the water further for the same pressure drop.    

As a guide. -  If you intend to try to run 400m or more of LeakyPipe at one time, - Choose 20mm supply pipe to transport the water.    I'd suggest if you're using 100-300metres of Leaky, you can use 16mm supply pipe.

16mm supply pipe is available here in lengths of 50m and 100m
20mm supply pipe is available here in lengths of 50m and 100m