A great landing page are short, sweet and uncluttered.
A landing page should offer all the necessary information,
but not so much as to overwhelm (and as a result, drive away) the visitor.
Provide the essential info that will interest your audience and nothing more.
Here's a great one: fluidsurveys
About the website firm, you can actually hire someone in this forum,
most of the members here are web developers and web designers, there's even
SEO's here. You can even try to reach the MOD's for they can be more trustworthy than other members
But if you really want to try some web design firms,
you can try custom web design, but I dont know if they fits on your budget.
(just a suggestion though, not forcing you to follow).
Hope this helps.
Edited by Lou Neri, 19 April 2016 - 06:15.