I have used these in the past - The PR Electronics unit is quite reasonably priced in NZ not sure of the pricing in the US.
Also you could look towards a basic temperature/process controller to do the display, the Omron E5CC basic unit has a scalable 4-20mA as an input option and is under NZ$300. Should be even cheaper at your end of the world.
for demo and test i am using pm435 with a 9 volt battery ( all displays separate battery) they cost around 6 euro are new.
with a simple resistor of 50 ohms you get a nice signal of 1 volt.
the dot is adjustable.