Oscommer Alterations/Addon Installation

I am looking at getting some addons installed on my oscommerce website, I have got the theme installed but need some addons putting on it. 1. Secure Trap (need to secure admin) 2. In the admin panel where the product attributes are I need another text area adding so I can add some text (SKU-NUMBER) which will show on the cart and also on customer invoices (see image) 3. Also need other addons - Discount Codes, Google XML Sitemap, Recently Viewed, Minimum Order before Checkout, Excel Import/populate and Excel Export 4. I have put 2.3.4 SKU Field_extrafields already but need this to show on product page 5. I need the + removing from the product dropdown box of the products Once this is completed then there may be other minor adjustments which will need to be carried out, we are looking for a long time relationship whth a reliable supplier so only apply if you have working knowledge of oscommerce with a proven record.