What rates higher in the eyes of google. A dot com with dashes or a dot net without dashes between your key words?
I think either could rank well as long as they have the keywords you are targeting. If you focus on the content and the quality of back links for your site I don't think it should matter. I'm no SEO expert, but I've seen both rank equally well and it seems to be more about quality of the site rather than if the domain has hyphens or not.
For exact domain matches, a .net without dashes will outrank a .com with dashes (for the same amount of work) I've ran tests around these types of things, and I've found domains without dashes are simpler to rank than those that have dashes.
Anyway if you can register .com without dashes it will be better than the same domain with or without dashes in .net. Imnot sure about ranking... everything depends on links