First question, how horrible is the water there? If it's well water? I'd go full RO unit, if it's treated city water, carbon/sediment only (RO is a bit of a waste if all you're doing is drinking it). My MIL live on a farm, with some cows and other heavy poop animals near by, I refuse to brush my teeth when I go over there the water is so bad... needless to say I got her an RO unit (and seriously think there were health issues that have been averted as a result). My parents however, treated water from a city municipality, even if it's not terribly good.. I'd do just carbon & sediment.
So if it's city water, I'd go with whatever is cheapest as far as a 2 stage sediment/carbon unit, they're all made out of the same crap when it comes down to it. Hell order a couple canisters from BRS and be done with it. You could even tee off the output to the refrigerator for very little additional time/money, they typically have a built in filter (if they're newer), but you make those VERY expensive filters go a lot longer if there's cleaner water going into them from the start.