New “Available Stock report” with build to orders incorporated

Need a report to calculate "Available stock" taking into account "open orders" including components of the "Build to" orders so we can accurately determine the stock quantities we have available that we can sell on our website.  Have spec'd/scoped the requirements of the report, right the way to the step by step process, which currently takes me 30 to 60 minutes each time which includes multiple reports and exports and merging of data. When I goggle the issue/problem, all the responses say "no solution".  The fact that this is showing on websites as an issue means there is a problem.  Happy to send the how to someone so it can be developed, happy to contribute to the cost to develop.  Need a solution/report - please advise how I can progress with this. Your support team tells me this forum is my only option. Thanks, M.