If I wanted to go the SBC route, what specs would I want to pay attention to? There are many boards that are (or seem to be) well supported in mainline kernel,

If I wanted to go the SBC route, what specs would I want to pay attention to? There are many boards that are (or seem to be) well supported in mainline kernel, but I have no idea how to tell whether the wifi is well suited to this use case or the internal connection stuff... Throughput benchmarks are also few and far between.