Creamy head

I have a question about kegging and creamy top additives. I've just bought a corny keg with a CO2/N2 canister (not for the purists so I've been told). My tap also has a sparkler on it and I'm wondering if the addition of a creamy top solution is going to give me 4 gallons of foam! Has anyone tried this? Is it a step too far with the CO2/N2 mix + sparkler (normal ale one) giving enough head. This is only my 2nd brew so any advice welcomed.
cheers

Sparkler? Normal ale one... ok, gotcha. If you have the beer gas/regs, treat your self to a stout faucet with restrictor plate; otherwise, I don't think the beer gas is going to do much for you. Better off with CO2.