Awhile ago I found a Macbook 2,1 (2007) that runs NetBSD fairly well too. The only caveat is you pretty much have to replaace the firmware with Libreboot or Coreboot. The weirdness in Apple 32-bit efi loading a 64-bit kernel (from my understanding), causes some issues with trying to boot NetBSD. But replace it firmware with coreboot/libreboot works great.
Its an older machine but does really well with NetBSD. I mention it because I picked mine up off craigslist for ~$20. You can find them on ebay for about $50.