can anyone tell me what is the correct offset. I have heard 5-110 as well as 5-115 and what are the offset ranges I can use with a 19' wheel and 235 wide tires? 40,41.42..etc? thanks!

Those offsets should all work

The stock wheels are 5x110 bolt pattern
18x7"
+41mm offset

The safe range on this car is +35mm to +54mm offset

www.TireRack.com is a very resourceful site for wheels though....check it out!