Gordon Crabb has a library of stock photographs which provide the raw material for many book covers. "Girls" are divided into centuries, there's a "Literary Fiction" category, and some Men and Children. Use these images for your visuals and you may find that you have a ready-made book cover.
I have high resolution files of all the images so contact me when you need them and to discuss fees – or to commission a new illustration. If you'd like Gordon to add other elements or alter an existing image then just let me know and he may be able to do that for you as well.