does eibach make lowering springs for the '05-'06 focus yet? cuz thye changed the whole suspension in the front...like the struts are different and springs...thye struts are a lot wider than the older versions.. :\
Coil springs are the same for all of the foci ; all eccept wagon from 2000-2006 . I am a parts manager at a ford dealer and went through the same trouble trying to find a set for mine. I ordered a set listed for 2000-2004 and they went on without a hitch. You realy need to get a good drop (2.5"-3") cause my springs are 2" and it still sits like an escape, handles better though. 
the struts are actually bigger in diameter...they changed some stuff..i have lowering springs on my car now (pro kit from eibach), but i had to kinda modify the strut to get the spring to sit..because the stock coil spring goes from BIG to really small near the bottom where it touches the base of the strut for the spring to sit on..i would have stayed, but i just put a little lip on it for insurance purposes... (been that way for 4 months now.. no problems) the back suspension is the same though...
focusin..btw, how much for that setup? thye make the sportline springs with that same thing? springs and dampers?
You drive a focus so the tires are going to wear fast even if you dont lower it, but i think as long as you get somebody you trust to do the alignment and they put every thing right it should be ok. Ive put 20k on mine since i lowered it and no odd tire wear as of yet.