Anyone offer any advice on which fuel flow meter in 57mm hole size is the best?

i've asked a few guys from the airport and can't seem to find anyone who knows much about them really.

I want something that will show ltrs per hour in real time as i'm fed up with the LPH really altering on any aircraft i fly and this way i will really know i've struck the optimum for the trim or rpm i have set and want to fly at. I guess by flying with a little drop in rpm or different trim could make a big difference to i want to do in litres per hour. If it has more features than just that reading then so be it.

Also i run a 80 hp 912 so i'm needing info on whihc sender is the best and if they will still floweven if the impellor thingy gets jammed and also whihc is the best way to fit the sensor.

for example are we best fitting them in the single fuel pipe before they split off, or on 1 carb (does the system lt yu multiply flow?

What do the boys doing the comps use to get the maximum set in endurance anyone know? Paul D any advice?

thanks and any advice would be great as i want to buy once and buy right.