I've heard good things about the Sony VIO for multimedia. Been a while since seriously shopping.
I have 2 Dell Lattitudes (C810 - 4 years old but very adequate and D505 1 year old). Both have 15.1" screens, but the D505 didn't offer the ultra resolution so not as nice for photos. The D505 motherboard has also broken 2 times. At work, I bought a D505 for someone and their motherboard has broken 3 times. My keyboard is also sticky - in fact, one USB port and the serial port on my 505 are broken again so it's time to call their service. Lucky thing I have 3 year on-site support.
The C810 had a hard disk failure but never any other problem.
In short, the cheap Dells seem to be cheap. I paid $3K for my 810 that's never broken, and $1800 for the 505 that has peripheral problems.
Note: the 505's archetecture seems solid, never a hang or memory issue, just the motherboard ports and keyboard.
Also; you probably don't need Windows XP Pro (its for corporate networking), and for photo work, more memory is better. 512MB is inadequate, 1GB should be fine, but 2GB would notice an improvement. For photos, I'm not sure why you don't care about disk space, in any case, 100GB seems to be the largest.
$1700 seems low.. Or - go down to Costco and get a loaded Sony for about that much for a loaded Sony.
I could also recommend a USB attached external hard disk for storing your photos. That way you can easily exchange photos with your desktop computer. I got one that's network attached so share photos easily between the 4 household computers without moving things around.
Wireless; they are all typically compatible, but the wireless transfer rate is painfully slow as compared with hard wired 100MB (probably less than half). I usually plug in to transfer more than 3 or 4 full sized photos.