If anyone could do me a huge favor and photoshop both of these 20" rims onto this CTS as best as possible I would really appreciate it. Thanks in advance!

I don't think that either of those will look good. The CTS rims on that color car are cool. V's are even better, but if you want to see options, use one of these wheel simulators: (personal pref = Tire Rack)

* http://www.tirerack.com/wheels/index.jsp?camefrom=&fromIndex=true&index=xx
* http://www.autowaretech9.net/nextwheels/newstal.htm