Ian,
You could do a lot worse than visiting Clarence Harrison's website. The link following will take you to a page where he not only has a link to his (free) rule set, "Victory Without Quarter", but also (just above it) a series of links to an article about "Creating a Wargames 101" with many excellent photos of ECW troops.
http://www.quindia.com/studioart01.htm
For a slightly later "Pike and Shot" period, Barry Hilton's "Under the Lily Banners" rules available here for the War of the League of Augsburg may excite you as well. Take a look at the Galleries at the LoA site for more inspiration. (Note that the LoA Gallery is located near the bottom of the gallery link):
http://www.leagueofaugsburg.com/gallery.php
I hope that these links help you.
-- Jeff