SaaS Development

I'm in the very early stages of this startup and I'm looking to build my product as efficiently as possible. I'd like to construct an integration to HubSpot, that takes specific data points about opportunities in a sales pipeline, runs them through an algorithm, and provides a percentage likelihood on all of your opportunities to potentially close. It essentially would be a much more accurate way for sales leaders to forecast how much revenue their sales reps would be bringing in over a given time period. I would also have to figure out how I would visualize this data once the integration was completed (a login on my website, a browser extension, etc.)

I'm currently researching inexpensive options like Tray.io, Zapier, Prismatic, Boomi, Workato, and others as I don't believe this is a very complicated project. I would love to hear based on what you know so far, how you would potentially build this product.