There are lots of articles and blog posts on SaaS metrics for the typical monthly subscription type SaaS companies, but many of the metrics offered don't translate well to the enterprise/annual contract SaaS world. What metrics work well for businesses that deal with longer lead times, lower churn, and annual recurring revenue?
Sales cycles for enterprise software sales are always longer than sales cycles for consumer software sales, whether SaaS or not. This is because large companies are slower to make decisions, you have to figure out who the decision maker is, etc.
So you need to keep in mind that your sales may take six months to a year to close. Cost to acquire customers is therefore higher (at least initially) than it is for consumer-focused software. Take all of that into account when you start to model your business.
I'm happy to jump on a call with you if you have more questions about how to model this.