Joomla help

I'm looking for programmers that can pick up where another left off. I had a programmer that was doing freelance work and is now working for a web company and his employment agreement requires him to not support other sites. So, I need to find somebody that knows Joomla, databases, search functions within the web page and e-commerce software. Right now my site is using Ambra Subscriptions and Juga to handle the e-commerce sides of things. I need somebody who can go in and tweak some codes and/or settings and get the functionality set up properly. What would be your hourly rate for work like this? Do you have experience doing these types of things? Can you handle custom tweaks of modules and other plugins? How fast are you? Thanks!