Write some Software & Create HTML email Alerts with links

I am creating a website myself via wordpress but would like something integrated within my site which I will need help with. My website, [login to view URL] which is under construction will be for customers looking to sell their unwanted video games. I will have a 'sellers enquiry' form on my site to enable users to upload pictures of their items along with providing a description etc. The thing I would like is some sort of order tracking within my site which allows users to see where the order is at. The login area must be designed with the look of my site. I would also like there to be a checkbox on the 'sellers enquiry form' to include sellers onto my subscription list if they choose to tick the box. The steps in the tracking of the order I see as the following:- Sellers Enquiry form completed by seller Seller enquiry being reviewed by us Offer sent by us offer accepted/declined/countered by seller Items collected/sent Items received by us Items inspected by us Payment made by us I would like this whole process to be electronically automated such as once the form is completed by the seller an automated email alert will be sent to both the seller/us, with relevant instructions included in the email. For example the email alert for the 'offer' must include the offer amount and a link to either accept or decline. The status at each stage should automatically change throughout the process so once someone completes the form the status will show as 'received/being reviewed', and once offer has been made by us the order will change to 'offer sent', once items have been collected tracking details are logged inside the order history and so on. The email alerts will need to be personalised with my business design using HTML and must include links such as 'unsubscribe', 'facebook like', twitter link, 'update preferences' and be linked to my mailchimp account. I will provide a template design but the HTML code will need to be created by the freelancer. Hopefully you follow me on this and hope to hear from you soon if you feel this is something you could assist me with?