Modify a Wordpress Posts File

Here is the brief:

Based on the twentyten theme, the current page requiring modification is: http://www.confidenthorserider.co.uk/category-index/ plus maybe other WP files. This page is generated from php script in a file called categories_directory.php

1. Create a Category list page like http://www.horseandcountry.tv/advice
This is main page that S2 Member will divert to after a member has logged in
When the image or the category title is clicked, it will link to another page which will only contain a list of posts within that category, plus links back to the main category page

2. Create a Post List Page:
The post list will contain the title, and first line, + read more….
When a post is clicked, it will link to the full article
At the top and bottom of the full article, remove Wordpress functionality that lets people read the next or previous post. Those links to be replaced with links that return people to the entire category list (item d. above) – not the next or previous post.

Hope this is clear enough to confirm the price.
Thanks