To be honest, I thought you were looking at the aluminum. A 23in/58cm is a big bike, probably borderline for someone 5'10"--I'm 6' so, for me, 23" is about right.

But, that said, look at the other side of things....you've learned more about bikes and you've done more research, right? Check the site again next week--maybe the perfect bike will be waiting for you then.