Google maps project

I wish to create a website that takes advantage of the Google Maps API (or equivalent) to display 'listings' that users will be able to register/login for, and create. The ‘listing’ will contain various information (name, address, description etc etc) and a photo gallery (images the user can upload for the 'listing'). The listing process will need to capture the above information and then provide a map to allow the user to manually re-position the marker (i.e. geocode address first, then capture map coordinates if user adjusts marker position. The home page of the site will contain a large map with markers showing the latest 'listings' (over, for example, the last 30 days) and a search/filter facility that will allow users to narrow down those listings by date range (7-30-60-90 days etc), category (listings will be in one of a list of categories, or by a text input address search. Clicking on a map marker will have the typical Google map behaviour of opening a bubble with selected information and a link to the full detail page. Note that the system will have to cater for a potentially large number of map markers so clustering and zoom levels for the map will have to be implemented. The ‘listing detail’ page will show the full information provided at listing creation, and the photo gallery (to be thumbnail list with popup full image on click). I have need for specific user types, namely a 'private' user, a 'business' user and a business 'sub-user' which is a user associated with a parent 'business' user (‘sub-user’ is added by the parent business user) Services provided to a business 'sub-user' are charged to the parent business user (in other words a ‘sub-user’ is an authorised user (perhaps employee) of the business users account...hope that makes sense :) ). Only ‘private’ users will register via the website, business users will be added by site admin. I will need to capture location data for users (only ‘private’ users) when they register so that a user can set up a ‘notification email’, should listings within ‘x’ kms of their position be created.(i.e. geocode address and store lat/long values. Cron job to carryout periodic sending of notifications...to be set by site admin) Further to the user types I will need to be able to setup both per 'listing' charge fees and a 'subscription' system for users. As an example, I may wish to allow 'x' number of free listings within 'x' time period after which a fee is payable per listing, or I may wish to allow 'x' number of listings within 'x' timeframe for a monthly charge. This will also require an 'account' system that will allow me to control whether a user is allowed to have a negative balance and how much of a negative balance. Typical account transactional reporting is required such as total/period outstanding negative balances, total/period positive balance amounts etc etc to allow invoicing/reminders etc. I would be happy for this to be built upon the Drupal platform but this is not mandatory. This project does not include any styling or design requirements...just the working code.