I'll do this macros near:
Unlimited (Macro1)
/ja "Unlimited Shot" <me>
PPA (Macro2)
/equip ammo "Patriarch Protector's Arrow"
/wait 3
/equip ammo "Demon Arrow"
ONLY if Macro1 works then you activate Macro2 too and suddenly after your WS ! This way you'll never loose your precious arrow ;)
Doing PPA stand alone macro let you use your WS macro even if Unlimited Shot is not ready using a normal arrow ^^