Revisions to E-Commerce web site with ongoing maintenance

I have a high end online fashioon company. I am seeking a technician who can provide ongoing maintenance of the site and who can offer design services as and when needed. Also I need someone who is expert in creating and maintining Facebook and other social media pages and sites. The software is a wordpress/ecwid combination. The person must be able to demonstrate an excellent knowledge of these systems as the working relationship will be an ongoing one. Other skills will be clarity and the ability to communicate clearly. As I anticipate the relationship willl be long-term references will be taken. SO long as the budget and min hours are concerned, these are very much guide figures. Ideally the preferred candidate willbe beaed in the UK.