Appreciate the quick responses, guys.
TheLeggett: I’m definitely NOT supporting IE 6 or older. Other than IE, I’m figuring Firefox, Safari, and Chrome versions 1-3 years old is reasonable. I’m also 100% OK with Progressive Enhancement: producing a “good” baseline display for less-capable browsers, while making it better for newer, more capable browsers. I’ll probably use some CSS3 here and there for the newer browsers, mostly for visual enhancements.
cpj238: I really need to avoid a standard width. Several of the artists and photographers have works that are VERY wide and short, or VERY tall and narrow, and forcing a standard width display will look really odd and they won’t like it at all. (But if I did bite the bullet and enforce one standard width, I’d size the images in Photoshop, not CSS. I’d have more control over things, I believe Photoshop has a better resizing algorithm than browsers do, so I’d be able to use smaller image files and get better quality images.)
Not sure I understand how a max-height on the images will keep the image-details in place underneath.