The most cost effective drop would be to use the 00-05 FRPP 1.5" drop springs and SVT shocks and struts (about 300.00 from Tousley Ford). You will also need the Omni Kit by Massive. This kit allows the use of the 00-05 front struts and springs on a 06+ car. It costs just under 100.00. Unfortunately there just aren't a lot of lowering kits for the 2nd gen Focus. Those that are available tend to cost a lot more as well. Tirerack and CFM carry some kits for your car. Just remember you want both springs and shocks to do it correctly.
As for wheels, Tirerack has lots of good ones at decent prices. What we need to know to help you further is the tire size your interested in using. That will determine the wheel size, offset, etc. Tirerack has a nice feature where you can see each wheel on your car. If you're interested in their products, they can deliver the wheels with new tires already mounted and balanced (no extra cost for the balancing/ mounting and provided lug nuts) to your door ready for installation.