KW coilovers have the spring seat at the bottom like you are talking about.
my old FS thread has some pictures of the orignal seats, plus some custom ones i machined to gain some height.
FS Ford Racing coilovers, aka KW V1
May 2014 ROTM, June 2015 ROTM
for rally-x: '04 Liquid Grey ZX3
Build Thread: http://www.focusfanatics.com/forum/road-racing-rally/667378-thenorms-rally-x-build.html
Sold: '02 Infrared SVT