you guys should clarify what exactly you are trying to do here .. a barrows pure is just an account built around barrows armor with 70 def req .. which requires no questing whatsoever. now if you barrows gloves your are going to have to do all of rfd and its subquests here is a list of all quests that reward xp defense included http://runescape.wikia.com/wiki/Quest_experience_rewards a minimum level of 32 defence is required/gained to get the gloves from all the pre req quests and subquests
You would need;
barrows gloves (RFD quest)
Piety (King's Ransom)
Soulwars cape (Nomads Requiem)
Turmoil (optional depending on your build - The Temple at Senntisten)
Well thats the most important things I can remember..
this is normally for 70-75 defence.
And just look up the subquest for these main ones I listed.
It's up to you what you want... if you want the best barrows pure your going to need to do the quests for Turmoil, Veng, Neitiznoit etc, all these things require a lot of quests also done before hand, you will find yourself doing a lot of quests.