I just went through this process with a dozen or so reels of my dad's 16mm Kodachrome movies from the 1950s and can vouch for 1080p/2k scans. Here's a frame grab for reference.
I used a service local to me, Legacy Digital. Cost was $0.32/foot. 100 feet scanned at 1080p is just under 900 MB, so figure 1 GB per reel for storage.
Legacy uses a RetroScan frame-by-frame scanner; info at the link below. This seems to give better results than lower-end telecine's upgraded with 1080p cameras, in that there's no gate weave. File format is MP4.
For anyone with older, small format motion picture footage: I had my grandfather's 9.5mm Pathe and Kodak 8mm footage transferred by ColorLab in Rockville, MD, on their custom-adapted Rank Cintel telecine. Decision was driven by age and condition of the film, especially the Pathe which was shot in the 1920s and early 30s, along with ColorLab being the only service that could handle the Pathe format. Not inexpensive, but worth the investment to preserve aspects of my family's history.