1-2 sounds resonable, but I have had problems with 2 seperate keywords. One will always be more dominant than the other.
I think creating a separate page with your second keyword could help out as well.
I have a client where the second keyword is the file name of an html page, and it shows up on the first SERP page even though the home page content is different, but relevant.
Example= "www.site.com/keyword-2.html"