You only want to run one charger at a time or both? Those are 80watt chargers so to run one at full power it'd take ~100watt power supply(chargers are typically assumed to be 80% efficient). To run both, you'd need ~225watt power supply.


Here's one that will do either and its $70 -

http://www.progressiverc.com/index.p...er-supply.html


Here's a PS that would run just one charger at a time -

http://www.amainhobbies.com/product_...-138V-10A-130W


And a word about your wanting to charge a 4S at 5amps - that requires 84watts (16.8v x 5a = 84watts). Your charger is only 80watts, it will get close to 5amps, but as the voltage of the charging lipo gets to 16.8v, it'll only be charging at a little over 4.7amps.