David,
Both of the wheels "Kasai & X-Factors" are HMC Chrome...It is the newest thing that has come out in finishes...Has the shine of CHROME and the charectoristics of paint...I am telling you that when you look that these wheels you are imdediatley impressed with them.
The 19X8's or the 18X8's are not going to affect the ride control "ARC". They will fit on the car with no issues what so ever...The recomended tire size is:
245 or 255-40-19 these run around the stock tire height. I have a set of the 255-40-19's and they run 27" tall, which will fill the wheel well up real nice. It depends on what you want. Paul Zimmer went with the 245's on his car. He should be posting pics of his X-Factors soon...
Brad