So Im building a focus RS rep and just need to know if you can fit 18x9 with an offset of 20 on a focus SVT (the same as a st170) with the RS kit?

The SVT\ST170 wheels are 7 inchs wide with an off set of 49 which will make the wheels Im looking at have an inner clearance 4mm more than stock and will stick out 54mm.
http://www.morfed.net/wheel-offset-calculator/

The problem Im finding is that I can not find a nice set of wheels here in the US with the right PCD and in 18x8.

These are the wheels I have found and are being sold as fox body mustang wheels and work out at a very good price.