Hello CDaustralian,
Yes, we can help you to modify your existing site.
Kindly share your existing site URL & requirements in details so that I can get a clear idea about the total scope of the job.
We have very good experience in website designing and development using WordPress, PHP, CodeIgniter, CakePHP, Laravel, MySQL, Ajax, HTML5, CSS3, Bootstrap, jQuery, JavaScript etc...
Let's discuss more details...
Regards
Sukant