Develop single page with Google Maps and API interaction

I need to create a single page that would consist of three elements (Google Map + table + form) as a showcase of API possibilities. Aim of page is to allow user to choose point or polygon on map and parametrize request to API, that would return result of spatial calculation. Detailed description 1. Page should contain Google Map, table and form a. On Google Map, user should be able either to create polygons, or create points, similar as here ([login to view URL]) b. Table should contain info on all objects created on the map (as right hand side in example), and later add column with result of calculations from API c. Form would let user define the request to API (calculation type & parameters) 2. Form would need to dynamically change based on previous choices of user. i.e. if in first step user might choose "calculation 1" and "calculation 2". If he chooses the first, he can narrow down request with 3 filters. If second, there is one filter etc. 3. Send request to API. Request will contain a. Objects created on the map, as GeoJSON b. Calculation type c. Parameters to calculations (i.e. filters, sliders etc). 4. API will return calculation result for each of objects in form of JSON – site must parse and place results in table