Develop API connection from wordpress site to Hostaway

We have a new wordpress website where we need to integrate into Hostaway's property management platform. We have tried their wordpress plugin and calendar widget - neither of which work as we need. We are thus in need of two items:

1. We need a simple availability calendar to be displayed on one page.
2. We need a booking request function built that gathers the proper data, allows for date selection from available dates, displays estimated cost of the rental and then submits that info into Hostaway for follow-up.

What would you quote to build those and integrate them into our existing wordpress site?

Bill