Excellent deck, Mordecai, though I think Mox Diamonds are 1 to a customer in T1. He'd probably have to go with the Mirage Diamonds instead.
Personally, I've always thought G/W was a fairly weak combination of colors, with the exception of Erhnageddon. Everything Green can do, White can do better. White, arguably, has better weenies than Green (evasion, protection, first strike). White has better control hands down, and if your opponent throws down a Moat, or a Stasis, there's probably no better finisher in the game than Serra.
Which brings us to another point. T1 is all about cards like The Abyss, Moat, and, of course, combo decks. To combat these things you'll need to play with Artifact Creatures (or Pro: Black creatures), fliers, and counterspells. If you can't play a deck featuring those 3 things, in some measure or another, you'll need to play a really fast beatdown deck to have a chance. The best of those are mono-colored.
I don't know what kind of cards you've got to work with, Spiff, but it seems to me that if you're on a limited budget you may want to consider going mono. For T1, I think the colors to look at would be Black, with discard, Hippies, and Black Knights (Pro: STP's

), or White, with STP's, Disenchants, and Protection from X creatures like White Knights and the shadow guys. Throw in a Scroll or 2 if you got 'em, or if you don't, consider White and use Armageddon and the Armor. Sure, the 'geddons are expensive, but that's one card that they'll probably never rotate out of the set, and a good 'geddon deck almost always has a chance to win. They're a pretty solid investment overall.
Hope that helps!
