CHeck out smalldog.com, if you're willing to go refurbished. I've frequently purchased refurbs in the past, and have been generally happy with it. Worst case scenario, I've had to use the warranty service to correct screen defects.

I picked up the 15" that you've spec'd, and I'm very happy with it. I think the extra RAM, disk space, and (most of all) backlit keyboard are well worth it. The superdrive is nice, though I've honestly not had occasion to use it that much. I suspect my appreciation for it will increase as I improve my backup habits.

The keyboard really is nice if you spend any time at all in low to no light situations (think hotel rooms before sleep, dimmed flight cabins, etc.). I think shipping any machine with less than 512mb should be a crime, too.

Good luck.