I can help build SaaS marketing plans with a solid strategy. I can exactly articulate pre-launch, beta, launch and post launch marketing strategy. And I can exactly tell you how to get first 1000 customers to your SaaS business.
I would suggest a few things before going live.
Create a pre-launch page. (Use LaunchRock)
Build your list from ground up. (Start blogging)
Integrate a referral program like Trevolta did. Make them share your voice via social media to get ahead in the list of invitees for the product launch.
Create a pre-launch video.
List your product on Betalist and other similar websites to get beta testers.
List your product on ProductHunt, Hackernews, Reddit etc.
Create a press kit so journalists can find about who your are and what you do to create a story.