I actually use a belt with enmity and HP, which helps get my HP to 4k. You can't put HP on a sword.

IMO, the best advice for gearing PLD is to follow a hierarchy of materia.

Enmity > STR > MND > HP > DEF > VIT


You can get a ton of Enmity from jewelry, Sentinel's Sabatons, and non meldable gear like the militia set (which is awesome for PLD btw and can rival even triple melded gear).