So you are doing a drop? Honestly, I only see drops on bigger wheels while lifts generally go smaller; you may be the first I have seen want a drop with 18s. That being said, post up what you decide - I imagine 285s would be the choice here...
Honestly, not sure if I'm going to lower it but either way, as I get older, I'm more about function over fashion. At 6'3" I can pretty much slide in but still use the step to exit. Lower it 2" and I'll be golden...easy entry/exit. May be enough to remove the running boards...? Well, that's until the 5'3" wife complains lol.
To further this point, it's the reason I'm going down to 18's. I tried 20's in XL and there wasn't much ride difference so I sold them and reinstalled the 22's...as of late I've decided to give 18's a-go. Especially after reading the positive feedback in this thread.
285/60 = 31.5" is stock OD for an LS trim but to me is too much gap when compared to the 32.8" that are currently installed. Meaning, a 2" drop on a stock LS with 18" doesn't look out of sorts. Yeah, at this point I'm splitting hairs over appearance, cost, and comfort to obtain the objective. But hey, you want what you want...