Expert Magento developer required.

We are looking for a certified Magento developer with an eye for design to help us finish developing a project. We originally hired a development company to build a new site for us but it turned out they do not have the skill set for the type of project we required. We are a manufacturing company producing bespoke windows, doors and other furniture. The website needed to allow customers to enter their own specifications, width, height, colour etc which would in turn amend the price paid by the customer in real-time. I employed Mico to set up their custom math pricing plugin on our server which works well and has allowed us to incorporate the flexibility we need. The functionality of the site now works correctly but we require some work to be carried out on the skin. The site will require some additional and ongoing work, updating Magento, adding additional features etc as the site develops. We are therefore looking for a developer we can form a relationship with, to deal with any work or issues now and going forward into the future. As we want to form a long-term relationship it is important that the successful candidate can meet all of the criteria below. 1) It is important that the successful candidate has an excellent if not perfect grasp on the English language as we have had issues with things getting lost in translation in the past. 2) You must be a certified Magento developer. We don't want any problems with the code in the future and feel that anyone that has taken the time to achieve Magento certification will be able to stand behind their work. 3) The functionality behind our Magento site is based around Mico's custom math pricing plugin. It is therefore essential that you are familiar with this plugin and the formula's it incorporates. 4) We need you to provide your hourly rate. Thankyou, Martin.