Hi there,
The level of customisation and usability you're looking for at this budget would be best implemented in a bespoke excel spreadsheet. A cloud-based solution would likely cost you significantly more and be less adjustable.
I've put together spreadsheets like this for banks, investors and businesses in Australia for more than 8 years, and I'm confident I can put somthing together for you which will do all of the above including actual vs budget, categorise by cost centre, purchase order schedule, purchase order to supplier order and cash flow budget.
Happy to discuss any details to get you comfortable I can complete the task.