Change Wordpress Theme for Consultancy / Training Business

For a Dutch customer of mine (a training & consultancy buisiness), I am looking for somebody who can change the current Wordpress Theme in a quicker, more SEO proof and responsive free theme. Also the current "Fitmanager" Plugin has to be maintained. The job: - Select 3 suitable free Wordpress templates (the URL of the current site I give by PM)Which are Quick, SEO proof, Responsive and suitable for Fitmanager Plugin. - Wait till my Dutch customer makes a choice out of the 3 templates (1-2 business days) - Change the current Wordpress into the newly chosen one, with working Fitmanager Plugin, with the existing images and texts. - With a short as possible Downtime. - Max within 1 week, projected time max 4 hours for experienced Wordpress specialist.