one thing to consider is where the discharge of wastewater is going to go.
even a high quality recirculating RO system is going to at best be around 3:1 product:waste water ratio. Lesser quality units can be as much as 1:3 or 1:4 product:discharge (waste) water. make sure that the system has a suitable boost pump as part of it to help with efficiency. low pressure = lower efficiency. most membranes that i'm familiar with are GPD rated for 50 psi at 50*F. this also helps so that your well pump isnt taking the load of the strain of keeping the membrane under pressure. if you can increase the pressure via a boost pump to lets say 80 PSI, you can significantly increase the production capability of the system.
if they're going to utilize the full capacity of the RO system, they're going to need to be able to dump minimum 2000 gpd (and possibly as much as 20,000 gpd) somewhere where its not going to cause harm to the local ecosystem. the brine (salt) concentration on the waste is going to be higher than the well conditions so keep that in mind.
second - the well of course is going to have to be capable of producing consistently 8000-12000 gpd minimum
i used to be a spectrapure dealer some years back, and we owned/used one of their 1000 gpd "pumped up" commercial units. i would strongly suggest getting in contact with them (or a similar quality company) and get their recommendations for the situation. even if you dont go with one of their units, they should be able to provide him the kind of technical information needed to achieve the goals necessary for that village.
a further consideration, since RO water is nearly chemically pure H20 and has zero buffer capacity, theres likely going to need to be some sort of PH treatment added if the piping system has any lead components to it. if the water goes acidic, you could easily end up in a situation like what happened here in Flint, MI where extremely high levels of lead were leeching into the drinking water when they switch to the flint river and ph treatment protocols were ignored.