Ask HN: Cheap/fast/reliable cyber-cafe for Haiti

I've been wanting to some day set up a cyber cafe in Haiti, with the intent of providing opportunities such as internet careers and education for the people. The requirement is for the user to be able to do more-or-less anything online, but do it for very cheap in locations without stable electricity or fast bandwidth.

I'd set up thin client software such as FreeNX on Android tablets and connect them to an AWS Linux desktop. The tablets would use an OTG cable connected to a powered USB hub, and plug into that hub a physical keyboard and mouse. The hub would charge the tablet.

I've found that 7 inch tablets, when positioned about 30cm from the face, appear to the eyes to be about the same size as a full desktop monitor. Most have the same resolution as a standard monitor. They can run on solar and have internal batteries for running after the sun goes down. Can be wrapped in a bump-resistant water-resistant case with a screen protector. And if they're broken or stolen they're cheap to replace. They can be locked at night in a very small safe bolted to the ground, so security is cheap.

FreeNX reportedly uses 20-100kbps, so several users can share a single connection, and it tolerates higher latency and disconnects.

I would use two cell modems positioned near 2 different towers. A local router near the users can select which modem to use, and a wireless backhaul such as AirFiber connects modems to the router. If one tower goes down, a local admin simply flips a software switch in the router GUI to use the other tower and everyone keeps working. Downtime of less than five minutes.

The local router would lock out browsing to any website and only permit a connection via a VPN connection to the AWS server. So someone couldn't just come along, connect their smartphone to the router, and abuse the bandwidth. They would have to use one of the tablets, and access would be controlled on those.

Any obvious mistakes with this approach?