wordpress tweak (re-open)

This is the re-open of the project I had before and and that was pissed off by a freelancer. Please make sure you have the necessary skills before bidding on it. I need some tweaks to the comment section of my wordpress blog (self-hosted): Below each comment I need a "reply" link that will display the comment form so the visitor can reply to that parent comment. The form must display right below the parent comment using ajax (with more padding from left). Wordpress version 3.1. I don't mind whether you have your custom solution or use a wp plugin, just need something that works.