i need someone to custom build a spreadsheet - asap please

We run a property development company and would like a cost / return / profit forecast document. Each project is broken into 3 stages - (1) pre-app / (2) planning / (3) construction, and we could potentially cease the project after any one. We would need to input costs / returns for each of the phases, with sub-totals and profit calculations. The summary document would potentially be in gant chart format, similar to microsofts standard 'gants project planner'. the start date and duration for each project would be inputted. A period selector would then highlight a month, and provide an output calculation for total costs / returns / profits up to and including that month. This is the core requirement. Added functionality would come from the ability toggle on/off whether the returns for a project at stages (1) and (2) should be included in the total, as we would like to plan which may or may not be seen through to the end. We would like this document to run for 3 years, but have scope to increase easily, as well as ease of adding further projects. Hope this is clear.