CLASSIFIEDS PHP SCRIPT MODIFICATIONS

I need someone to build me a website which functions in the same way as [login to view URL] The project will involve finding the correct script to use as a base for the project and modifying it to my requirements. The key points which are need are: 1) Ability for visitor the website to register as either an individual or a dealer. 2) If you look at [login to view URL] homepage I need featured items appearing/disappearing. 3) The website would need a dedicated search page, with bullet point drop downs exactly like this page [login to view URL] broken down into sub categories etc. 4) The homepage would need to feature 'Latest Guns Added' as you can see at the bottom of this homepage laid exactly just the same: http://www.guntrader.co.uk. 5) When someone signs up to the website, when they post an advert the cost of the advert would depend on how much the item is selling for and this would need to be calculated automatically. For example, if someone wants to sell something for between £0 - £500 it may cost £10 to advertise. If they want to sell something between £500 - £1000 it may cost £20. Thank you Steve