this domain is strictly for search engine optimization
As others have said, get both at this stage in case things change.
Having said that, for pure SEO dashes seem to win for me.
I have many pairs of domains (with/without dashes) that have similar auto-generated parked content and are linked to from exactly the same place. The dashed version gets *much* more traffic in nearly every case.
One reason for the difference could be the repetition of the domain name within the auto-generated content (dashed version separated better), rather than just the domain name, but whatever the reason the difference is very marked.