I always build a factory first, that way you can build engineers that swarm out and claim new mass ASAP. If you build 1 fac, 2 power, 1 mass, more power and go from there, your start is ideal, IMO. I'm not sure which patch version I'm usually playing, though, because I remember this plan once failing hard, because they tweaked building costs, either in a previous or later patch.
Also, before you have T3 gunships, I have already ripped you apart in a T2 land rush.