For the fit your tire size matters more than them being 18.
A 235 55 17 has been used on a stock height leaf and that is larger than most 18s you're likely to use.
As for range loss the tire choice and rim weight matter.
You can pay for 18lb 18in rims, it'll be big money but they won't be as bad as some 26lb 16in rims.
There are almost zero LRR choices in 18 and 19 though. That being said LRR doesn't mean much more than they tried to improve fuel economy. There's no standard to say what it needs to get for them to slap that label on.
