Lord Ben said:
Okay, you destroy them if you turn double their HD. Are they destroyed forever or do you still need to still stake them in the heart, destory their phlactery, or lay their souls to rest?
Slightly inorrect
You do notneed to have double their HD in Turn Effect.
Your Cleric needs to have a level dopuble the HD of the undead in question.
IOW, for a 4HD undead, an 8th level cleric will destroy them
every time.
Specifically, PHB page 140:
Destroying Undead: If youhave twice as many levels (or more) as the undead have Hit Dice, you destroy any you would normally have turned.
Levels, not turnign damage, is the key.
Now, as to the core of your question: yes, they are utterly and permanently destroyed. Gone forever, not coming back, and so on (barring later magickal intervention; one supposes a Wishor Miracle could return a once-destroyed vampire to unlife ... maybe ... if the GM wants it to work that way ...

... ).
The Lich is a special case. IMO, yes, you WOULD need to still find the phylactery -- as that is, in essence, a pre-prepared means of "later magickal intervention" aimed at bringing the Lich BACK even after destruction by some means or other.
So the Vampire is screwed, the Lichis merely ticked off.
