Building an effective SaaS landing page can take a while, especially if you are not very experienced in coding and web design. So, I would recommend you to check out this agency called Eleken. This is the company I personally trust and if you try working with them I`m sure you won`t regret it too. You can look at SaaS Design Agency - Eleken (http://eleken.co/) if you want to see some examples of their previous works.