Hi! I was looking for new projects and saw this one, decided to bid on it. I found it interesting and I believe I have all the knowledge to make a good work. I have to confess that I don't know Vivvo (I had just browsed their website), but if there is a good way to export data (even if it is inside the database) from it, then it has a very good chance to make it work almost perfectly.
I'm a Drupal expert (also experienced with Wordpress) and I believe that you should consider this option over Wordpress. For such this huge amount of articles, Drupal can treat them better keeping the performance on a high level (of course, it depends on the environment it will be installed too). Default Wordpress has none about performance, and it depends a lot on 3rd party plugins that sometimes doesn't work well together.
I'm able to do this complete conversion to you, as you asked (including the 2nd part). I believe that my price and time are fit for this first part of the job.
Just to present a little about myself, my name is Marcelo and I'm from Brazil. I am a CS graduated with more than 17 years experience in IT market, and +8 years experience with Drupal, mainly development, SEO and performance tuning. I have other some good works at my portfolio. I'm closer to 100% conclusion rate and positive feedbacks here at Freelancer.com and I intend to keep that.
If interested, call me on chat or award this bid!
Regards,
Marcelo.
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