I have really thick hair how many bundles will i need

At least six bundles in my opinion

How many packs needed for shoulder length faux locs?

Usually 3-6 packs can full a head. I suggest you buy 6 packs if you want thicker hair. 3 packs / order.

What do you moisturize the crochet hair with?

When I use this hair I clean it with apple cider vinegar by soaking the hair for 45- 60 minutes, rinse, then add whatever type of moisturizer to the water and let the hair sit it that for a few minutes,after rinsing the moisturizer from the hair I hang the hair up to let air dry. The next day if the hair is completely dry. I add my shea butter mix on the hair before I install it into my hair. Since the Marley hair is synthetic it's not going to keep the luster. The only reason I put any moisturizer on the Marley hair at all is because my hair is well moisturized before adding. I hope this helps.