I am owed photographs for some work I performed. Can I sue for photographs or do I have to sue for their monetary value?

You can sue for what is known as "specific performance", that is to have the contract performed by being provided with the photos for which you contracted.  This fits into the category of what is known as equitable relief (as opposed to "legal relief", i.e. money damages).  However, you should be careful because some courts, often including small claims courts, do not have the power to award equitable relief, and you would have to sue in a court of general jurisdiction, which might be more expensive than the matter is worth.