If you only need -100 CP from Headgear and find Uncomfortable, well... uncomfortable to enchant, you can always spam for a Thin ES and put it over a Stiff tailed cap.
Damn you're right. I COMPLETELY derped on the prefix -100s >.<
There are 3 -100cp prefixes: Thin, Small, Vicious.
Thin (Headgear): Just spam Lingering Darkness int+ and enchant it on a stiff tail cap.
Small (Handgear): Enemy Behind int+. Expensive/difficult to enchant. You need to sequence with Silver Fox or Burgundy Bear (can't think of a glove that drops with an r9+ enchant on it).
Vicious (Footgear): Their Method int+. A lot easier to enchant. Just raft (31+ *s) for a Glowing ES, or find a Difficult ES for cheap (most people don't want this).
The drop rate on these three enchants are pretty low from what I've seen. I've done hundreds of Their Method adv/hm and only got a few Vicious ESs.