I agree with others that said buy a house and get one car. Not sure why you'd need two pricey cars, but I'd personally go for the Vette. And don't assume it has to go away when you start a family - my Dad had a Vette as his only car the entire time I was growing up - works surprisingly well as long as the wife is cool with a 4dr./family car.
To answer your original question, though, I'd get the 545 as the first car and then add the Vette if you really want to spend the money. The 545 is a great car - very well balanced, nice power, and great for almost any driving situation. I have a soft spot for the Corvette, as I grew up with them, but some people don't think they can serve single-car duty.
Seriously, though, save your money.