The reason I said endurance is because elemental shield is not available at the altar(and i have beaten the main quest). Is there something I need to do or is it not available?
Let's make sure we are talking the same language here. When people say 'elemental shield', they are referring collectively to three seperate effects: fire shield, frost shield, shock shield. Each effect combines both a shield and elemental resistance to the effect in its name and is quite helpful. These three effects are certainly available at the enchanting altar. You simply need to buy a spell for each so it is in your spell book, then you can enchant with it. More info here:
http://www.uesp.net/wiki/Oblivion:Magical_Effects#Alteration
The reason sigils would have been nicer is that they go up to 25% strength. A grand soul at the altar will only get you 9% though. Still, it is a good enchantment.