Force carbonating with brew gas

I'm about to carbonate my first brew (stout) in a corny keg. I have bought brew gas (CO2/N2) and a stout faucet and was planning on using this gas to carbonate and dispense. Will this be OK? I've read many people use normal CO2 to carbonate then dispense on brew gas. Is this just for economic reasons? If you can use brew gas for the whole thing, what pressures should I use for carbonating and dispensing.
cheers

Use 35-45 psi for both. It will work just fine.

thanks. So 2 more questions...
1. How long should I leave it carbonating before drinking
2. Will it not over carbonate by leaving it at 35PSI (other methods seem to indicate lowering pressure to avoid this).
cheers

It should carbonate within two weeks. The purpose of beer gas is to avoid overcarbonation at higher serving pressures.

The reasons people carbonate first, then use beer gas are twofold:
1. Cost.
2. Speed. Pure CO2 will carbonate faster than beer gas.

Been curious about this topic myself. Glad it was asked and answered.

Salute!