I don't see a rear coil-over there ...
And there are very few true coil-over kits for the Focus. The rear is usually just an adjustable spring perch.
I'm not sure what you're trying to do, but it sounds like it's going to result in an unsafe and crappy ride.
There are a good number of proven kits available for reasonable prices. I'd suggest you pick on of those instead of trying to save a buck and ending up with a dangerous car.
Sleeves are and have always been a junk product. It's quite well known that factory (especially old worn out ones) struts/shocks can't handle (control) much of a spring rate increase, which is what is needed if you're going to lower (reduce spring travel) you car. If you expect to reduce travel by 2 inches and not bottom out, the springs need to get stiffer. The strut/shock can not handle and control this extra load.
Hence the reason for kits.