I'm also in the GSG 1911 camp. Buy one, shoot the hell out of it. Mine's got >3400 rounds through it already, it's just fun to shoot.
Another option you may want to look at is a used Smith & Wesson M&P9, either in your LGS as an exchange, or in our own Equipment Exchange. You can pick one up for around $500, possibly less. The .40 is usually priced the same as the 9mm, but the 9 will be cheaper to feed. Other's may disagree with me, but I've found that the M&P demands good fundamentals just like the Glock so it's a great pistol to learn on.