My vote is rent from National. There's a 99% chance you'll find a Camry, Corolla, or RAV4 on the aisle and they're all equipped with adaptive cruise control with lane-keep assist.

The Toyota/Lexus, Nissan/Infiniti, Honda/Acura, and Hyundai/Kia/Genesis systems all work great for highway driving. BMW and Mercedes also work great, but National usually doesn't order them equipped with those packages.

Best rent from an airport location though, they have a larger inventory and if you don't see something you like you can just wait a while or ask the lot attendant.