Yup what drchuck72 said was dead on. I was in the same boat as you, I opted out for 18's (also because the deal was good lol
) over 19's because of the weight issue. However it all depends on the rim also. Some rims in 19" look better over 18" rims, with that being said, other 19" rims can also look too big or "baller" IMO. What rims do you have in mind? I can probably post some pictures of the rims you're thinking about (I have probably a thousand pictures saved over the years when I was searching for rims
). With 19's you also increase your chance of bending them when going over pot holes.
I would personally go with 18x8.5 over 18x8 because I perfer the wider tires, but it's all up to you. The wider the tire the more $$$ also (in most cases).