Maintenance and revision of the site on OpenCart

We are looking for a company (private specialist) working with the OpenCart system.
The subject of the site is climatic equipment.
For an existing site, it is necessary to make a set of improvement works.
Main page (design), change of blocks.
Refinement of product catalog pages.
Work on SEO and website promotion.
In general, we are looking for a reliable company who is ready to lead the project, to be in touch.