It is easier to market it as a product with an annual maintenance fee than as "SaaS". I say this because there is an established process (GSA for feds, it varies by state and local) for selling products, even product with maintenance agreements.

Another route you can take, depending on the agencies you are selling to, is to sell it to existing federal contractors. There is usually a "materials" line in their contract for buying stuff to bypass the normal process. This is common with DOD, not sure about others.

Good luck.