Warlock Healthstone Warning
 

Is there a mod other than necrosis that will warn you when you soulstone cooldown is up?
(i don't like necrosis as its not modular)

I do not know if you consider this enough warning, but OmniCC will make your SoulStone, and pretty much all your other stones/spells/summon become thrice it's size when the cooldown is over, as well as big red numbers over the icon when its soon done (10 secs).
Myself, as a mage, find it quite hard to miss my Evocation cooldown being over using OmniCC ;p

Lylock will work for soulstone notification, as will RR Banish.

If you have FuBar you could get souljarfu.