There is either mixed gas 25% CO2 / 75% Nitrogen available in a cylinder or blended gas on-site where you can customize the ratio to any dispense situation.
The mixed gas in a cylinder is reserved for stout or nitrogenated beers were if you applied it to your brands it would change the flavor (flat).
The blended gas on-site system is rather pricey for home use. But if your budget can afford it, could be used at correct ratio at higher pressures to overcome inefficiencies in your system.
If you have a direct draw system such as a kegerator, you probably would be fine balancing the system with 100% CO2. Beer Temperature @ 38 F, 14 PSIG with between 5-6 feet of 3/16" ID line if you are at sea level
Scott Zuhse, Instructor
Micro Matic Dispense Institute