That's a beautiful steel CX frame.
I have three bikes with Cane Creek S2 Headsets and they're solid. They should last a good long time for the $35-$40 I paid for them.
The Avids are decent. The 4's are black and have one piece pads. The 6's are silver and have cartridge pads. The 8's are like 6's but have titanium bolts.
I'd get an old set of XT/LX/STX "M-system" cantis, or maybe the new Shimano cantis.