JSmokes you, of course, make a very good point. My suggestion for starting lower was simply so Packs can get everything else dialed in. Being that this is his first grow, he'll have a lot of moving parts to start.
Obviously, as he gets all of his parameters where he wants them and knows he can mitigate against heat, humidity, etc. and get his nutrient regimen dialed in, then the more wattage, the better.
Packs - this is good advice from JSmokes. There's a million ways to skin this cat. Just because I'd start off slower and lower doesn't mean others would...and there's nothing in the world wrong with hitting the ground racing! It really is going to come down to you weighing your options. What I love about this site is the divergence of strategy and opinion. To me, it's what makes the Farm rich.