Hi,
I am experienced WordPress developer. I can design a custom layout for your business accounting firm. The layout prototypes will be provided before working on any code, so you can be completely sure about the layout design even before we implement that. I will also be able to help you with content and graphics, if required. I am expert in Wordpress and I would highly prefer Wordpress for this kind of website.
Regarding the functionality, do you need anything specific? Or you are currently not sure about the features you might need? If you could provide some reference website or competitor's website, I would analyse them and would add similar functionality for you that would be matching with your business needs.
The layout design will be mobile responsive and I will also help you with on-site SEO optimization. Apart from that, I will also add google analytics and mailchimp integration and Social Media sharing as well if required.
Let's talk more about your website in private. I am ready to start work right away.