Looking for a Wordpress expert for a long-term mission

We have a website running on Wordpress MU. We are looking for Wordpress MU expert to take in charge the maintenance and improvements of the website. You will be tested on the first bunch of modifications. If we are satisfied with the work done, you will be asked to take in charge the long-term maintenance of the website. We evaluate our needs at more or less 4 days of work / month. Bid for the first 4 days of work. Give examples of what you did on Wordpress. We would prefer a Russian speaking developer.