Customize my Woocommerce Store via custom code

Hello we are looking to customize a woocommerce store adding some TAX related fields to checkout, orders details and order emails. 1.- We need to ask for Chilean TAX id on checkout and validate if is ok. This field is called RUT and there is already a php validation made for this here [login to view URL] a valid example for this field is: 11111111-1 or 6638321-0 (the number after the - validates the field) This field is a billing field and we want to be displayed on the order page and in the email along with all the others billing fields. 2.- we need to ask clients if they need a an invoice for a company. So we need to ask them If they mark YES, then we need to ask them Company Name (Razon social) Company Address (direccion) Company RUT (RUT empresa) Company Industry (Rubro) Company city (Ciudad) by default this is selected as NO (they dont need company invoice, personal invoice is ok) If they select YES and fill all the fields, those will be the billing fields and the personal info should be the shipping fields We have something similar on [login to view URL] but is not just as we want it. Its made with pluginss and custom code. We also attached 2 screenshots. One of [login to view URL] checkout form and the other of the email Please take a good look, if any questions please just ask. We look for a reliable provider, with experience al good comunitations skills. If everything is ok, kindly provide quotation and estimated time of delivery. best regards Daniel