First, there are official NuGet packages for the WebDriver based Selenium [1], and some extra selector support [2].
(There are also some other packages for RC based code and putting RC based code on the new WebDriver back end.)
And in F#, Canopy [3] is worth a serious look.
[3] http://lefthandedgoat.github.io/canopy/actions.html [1] http://www.nuget.org/packages/Selenium.WebDriver [2] http://www.nuget.org/packages/Selenium.Support