Convert existing site from PHP to RoR with Sphinx

Need to convert existing site [login to view URL] on RubyOnRails(RoR)with Sphinx. Let me give u an overview about the site-- Couon Section: it involves-- coupon posting through merchant controle panel, coupon display as per the local US zip, coupon image creation on fly and coupon print. Business Search: it involves-- business search by business name, category or tag and business location. Business Listing: it involves-- display business details on business listing page, blog posting and display, blog commenting, business review, coupon display if they have any, user can join any business(B2C) or business can join any business(B2B). Every merchant can post, multiple business for multiple locations and can manage all the business related activities from its controle panel. NOTE: I want to only those developer to bid who are very confident about handling site with HUGE DB and can make the search page run faster. Business search shouldn't take more then 6 sec. Project should be develivered within 60 working days.