The K8T ones (Neo2-F, Neo2-FIR) are based on the VIA K8T800 Pro chipset, the K8N (Neo2 Platinum) is based on the nForce3 Ultra. I don't think you'll be missing any important features with the Neo2-F, but it is not as good at overclocking as the K8N, or other K8T800 boards for that matter.
The 9NDA3J is a very nice motherboard too.