I red all thoughts till now and my advice is if you are going to buy a new hardware now (year 2015) take multi core CPU. The OpenBSD just get better every day and if you follow tech@, source-changes@ and misc@ you already know that our beloved OS soon or later will spread load on all CPU/CORES (device drivers, TCP/IP stack, pf and so on).
That's a good point in general, but this is an embedded project and it's pretty much set once made, so future expansion or upgrades aren't really a selling point.
