Data system for growing hospitality group in India

As a growing hospitality company in India, we are struggling with integrating old data with new data. All data has been stored via excel which includes a strong human component. I am looking to create a system that includes a database to house data on guest occupancy, invoices, reservations and be able to generate invoices based on the data. We should be able to have some flexibility in invoicing as one major source of our growth is our flexibility of product/service pricing. I would like to open this up further to house inventory and cost data such that I can get enough MIS in one location to generate true profit and loss across various views and drill-downs.