Google Top Ranking . Organic Traffic

Hi. We are doing great with Social media and SEO is good on our page. But we are lacking Organic Traffic because there is not much high quality backlinks and keywords that are ranking in top.

We are Shopify store selling Watches and would like to have customers to us through Google and other search engines as well . We are already getting daily 1000+ visitors from Facebook Which is great and giving us good sales.

Keywords we would like to rank additional to your suggestions is>
Free Watches
Just Pay Shipping
Fashion Watches
Luxury Watches
Mens Watches
Womens Watches
Fitness Watch

We are willing to pay additional $40 as success fee when we see the succesfull result.