Paul you could put the text on the pics - or create new (plain webcoloured background) file and make it slighty bigger height wise - move your pic over the top as new layer, put your text in the bottom seperate and flatten and then save for web
adding plain webcolour background wont add much to file size in a jpg
even then you would on have to make a index page as you say, maybe that is the only timely part, putting the link on the front of that as you say, would cut down on tediousness of sub galleries a fair bit
I like the way CS/PS does the thumbnails - very nice