You shouldn't experience any problems with a hyphen in the domain name. Exact Match domains seem to rank better, but most likely not directly associated with the exact match but the domain history and content. Even with a hyphen you get a close match. I have seen hyphen domains rank just fine.
The only concern I would have is consistency within the domain name. You may throw of users by adding a hyphen to an unhyphenated domain. Personally I would opt against using the hyphen. People have learned to read through domain names at this point.
If you do go with the hyphen make sure you redirect the unhyphenated version to the hyphenated version.
