Need some help to improve my build further

[Nerevar Telvanni]

I always like to max the Magic Resistance perk under Alteration, as well as the Atronach Perk as it always me to absorb incoming magicka. (I always play part caster on all my builds so you may not need this one).

Same goes for the Recovery perk in Restoration, but if you don't use magicka all that much you wont need this one either.

Avoid death (Once a day, heals 250 points automatically if you fall below 10% health. (Only if the damage does not kill you.) in Restro might be a good one.

I'd put points into enchanting as the gear you make is nearly always better than what you can find. If you can put a point into the perk that lets you have two enchantments per item.

Without knowing more about your play style I'm not sure what else to suggest.

 

[Nerevar Telvanni]

I K4 I

Do you have the Dawngaurd DLC? If so I suggest doing the side quest called: "Lost to the Ages" It sends you in search of the lost Dwemer's Aetherium Forge.

Once you complete the quest pick the Aetherium Crown. It will allow you to have two standing (birthstones) stones at one time.

I personally use the Apprentice Stone (Regenerate Magicka +100% & Weakness to Magic +100%)
and the Atroncah Stone (Magicka +50pts & Spell Absorption 50% & Regenerate Magicka 50% slower)
as I'm either full mage or battlemage type characters.

For you I would suggest the Lady Stone: (Regenerate Stamina 25% faster & Regenerate Health 25% faster). The Lord Stone: (Armor Rating +50pts & Resist Magic 25%.)

As for a particular place to find an item with X enchantment, I don't think there is one. I've never really noticed if I've gotten the same item from the same chest in the same room and different characters. Loot is random and the enchantments on the items are random. You might try vendors who sell clothes and jewelery as they sometimes have rings or necklaces that might have the enchantment on them.

Once again I'm going to ask about your play style that would help on suggesting other perks.