I'm switching to vacuum next year with a similar flatland situation. My thought was similar without the reservoir/float. The concept is to operate the pumps in series and lift the sap into head of the next pump segment to generate slope. I think it would be easier to keep the tight system with less parts provided the mainline is sized properly.
I'm curious to see what the experts think of this concept.
2013 - 25 taps - 2 turkey fryers
2014 - Taps on Bags
Home Built 2 x 6 arch, autodrawm sap hauler
RO - 100 GPH
2015 - 450 taps on bags.
2016 - Zero Taps - Moving -
2017 - 175 taps, Home Built Filter Press
2018 - 175 taps
2019 - 200 taps