NF4 vanilla, IIRC, is NF3 feature set with PCIe. NF4 Ultra also adds support for SATA II, has a few more networking features. The NF4 SLI is the Ultra with SLI capability,
As for NF3, the NF3 150 is an old chipset for S754 Athlon 64s. It had only a 600MT/s HT link, and has since been replaced by the NF3 250 and NF3 250Gb. The Gb has integrated gigabit ethernet and a hardware firewall. The NF3 Ultra has 1000MT/s HT speed for S939, IIRC.