Shopify Custom Codes

I need some custom codes for my shopify website. Here are the details :- 1) I am building a new jewelery store on shopify and I need a way to automatically add sub-sub menu based on producttags. For ex thereis a menu item metal so whenever a new product is uploaded with a new metal tag say Silver. it should automatically come as a drop down to the menu Item "Metal" 2) I am building a new jewelry store on Shopify. I had this on asp.net earlier so in order to make user experience better I need a way to add multiple filters on product collection pages so the user doesnt has to browse through 10,000 products. I need various filters like Metal, Stones, Product etc. All these information will be there as product tag so how can I make the filters appear on the collection page so that user can simply only browse through his/her requirement. Please help me on this.