I guess by conversion rate you mean turning visitors or prospects into customers.
This is perhaps more a marketing and sales question than anything.
As a guide, though, only qualified, motivated and serious people will hang around on your site if it's not clear, attractive and easy to navigate and use.
At first glance at your site, it is busy, conventionally "corporate" in feel, and it's not that clear what you do or why you are special at it. Is that what you wanted ...?
It might be worth going for a simple, uncluttered, high-impact design and message, with back-up data, details and supporting messages all off the home page ....
You might want to consider paying for marketing consultancy alongside your design budget - while the two are related, they're not really the same. Marketing - what is the core appeal that you are promoting? Web design - how will you deliver that appeal to web audiences?
But isn't this the pair of services you are offering others ...?