Not knowing your proportions, it's hard to say whether the 53 is too big. I'm 5'4 and have a 50 cm Bianchi women's specific bike, but I have short legs and long arms. Regardless, I would hesitate before buying a frame that's too big with the hope that I could improve the fit by changing out the sten, seat post, etc. For one, there's only so much you can do to tweak fit when the frame size is too big or two small. For another, you often compromise stability and handling when you do so.

A bike isn't a bargain if it doessn't fit. My advice is to test ride as many bikes as you can to get a better sense of what feels good. Don't settle for a fitting at an LBS that is based solely on your height. Sure, you have to be able to comfortably straddle the bike, but it's your reach to the bars that will most influence your comfort on the bike. There are things you can do to tweak it, but if the bike is fundamentally too big or too small for you in that respect, you'll likely never be happy with it or ride as well as you might otherwise. And don't necessarily assume that you need a WSD just because you're 5'4. Depending on your proportions, you might fit on a men's bike. Again, test ride available bikes and insist on a more comprehensive fitting.

I agree, too, that the look of the bike is important. If it doesn't speak to you in that way, I would wait until you find something that does. Remember that bike shops will soon have--if they don't already--their 2008 models on the floor.

Good luck!