long term part time Web Designer able to use OPENCART

PLEASE READ CAREFULLY: We do not need a new website building, we already have one. We are looking for a long term partner to help further develop our current website. Our company has a number of oversees employees working on various projects for us via skype on a day to day basis. We are now recruiting a part time web developer who is familiar with mainly OPENCART but also: Skills: Good Experience with Opencart anyone that knows object-oriented PHP, JavaScript, JQuery, CSS, AJAX, HTML and MySQL should be able to develop our site with these skills. Project: We have a website which is completed however, we need to make constant changes to the design, layout and features of the website. We are looking for a freelancer who can develop our current opencart website as we give instructions on changes to be made. Initially the work will be required for the first 1-4 weeks full time but then the work will be required on a 'few hours per day ' basis. Please respond only if you have experience with opencart and posess the skills above. The work starts immediately. Wage can be discussed and dependant on hours worked.