a real estate website and mobile application for android and iOS

I'm planning to build a website for real estate listing (house, apartment, bungalow, flat etc.) and also mobile application for iOS and Android. The website will be a part of real estate firm which enlists the real estates for sale/ hire/ lease. The listing should have details like name of owner, contact number, address, area of land, built up area, number of stories etc. I've summarized the requirement as follows: Search box by budget, rent/ lease, area of property, location etc. A separate sub-domain for established agents, housing companies etc. A separate page which displays real estate listing on a google map. A dashboard for registered users where they can view their listing, update it, modify it etc. A online payment gateway using Nepali payment gateway ([login to view URL]) etc. Actually since netizens in Nepal have no proper and established e payment gateways, they will deposit the money on bank and enter their transaction number and we manually verify it later. A wishlist page, where prospective buyers can enter their wishlist of property. I'm planning to make the website huge and i'm anticipating my clients to be on the number of around 10,000 -20,000. Wishlist clients database is expected to be around 50,000. And the requirement of mobile application: Should be able to display the available real estate on a map from the current location. Should be able to have a dashboard where they can upload pictures, and description of their real estate. I'm looking forward to hear from experienced web design firms and they are expected to submit their proposal along with expected time to build a solid website and the app, probability of future extension of features, and a very competitive budget.