I found a good site for free blog headers:
http://www.freewebpageheaders.com/gallery/
You need to register, but so far I haven’t been spammed. Seems legit to me.
One of the problems with WordPress is the difficulty in customising it. I guess it’s made for professionals, rather than amateurs like me. But even an amateur can use a WordPress template with a customisable header and then use a header from the freesite above.