Reviewing TTN Gateway PCB board,
I see it is using an Aria G25 module http://www.acmesystems.it/aria. This is an old (2 years) and quite expensive ($24) ARM linux module, has no wifi and needs an external wifi module.
TP-Link and 90% of the wifi routers in the market use Atheros. They run OpenWRT linux and there is a big community support.
I am also making a cheap gateway, I write a how-to for raspberry-pi https://github.com/mirakonta/lora_gateway/wiki and now my plan is to use a WIFI router with Mini-PCIe slot and plug a Multitech mCard.
For example this router is €30 in single quantity and $18 in 1000 units volume:
And the chinese manufacturer can customize it to our needs and with our logo.
I see the board uses two big LDOs. I recommend to use DC-DC converters because SX1301+SX1257 already disipates a lot of hot.
I see it uses a custom SX1301+SX1257 design. Was it easy to buy these chips? Semtech sells these chips to very few customers. Has someone the complete SX1301 datasheet?