Good looking build, Al.
Nice one.
As for the photo sizes....... I can only speak for Fotki, the photo sharing site I use.
After you upload pics, you can change the "display" size before it is shared.
I believe the max size here at STM, would be in the 650 to 750 pixels range for the longest edge of a photo.
I'm sure Tom could enlighten us on the specifics.