It would be a cool game to play if you were to use the perry bro's samurai miniatures, but the warlord rules. use usual samurai/ashigaru minis for the raider force, and for the defenders use the armed pesants/ikko-ikki for the pesants, and the unarmoured samurai as the magnificant 7.
i have a bunch of the mini's. they are smaller than warlord mini's (true 28mm) but it would be a cool historical alternative using great and simple rules.
check out the minis @ thewarstore.com or perry-miniatures.com