Database for assisting data cleanse activities, reporting, linked to web, multi user access

I require a database which will allow the importation and processing of up to 5 million records at a time. This database is to enable me to perform data quality analysis of my clients databases. This database will manage analysis on 3 main objects, with these objects having between 5 and 15 attributes. Using this data, I then require a series of database queries to be developed, to enable both reports and worklists to be developed. I may also require that these reports be viewable by my clients, probably over the web. I may also require that several instances of this database be built or cloned, so that different clients can access their protected data at any one time. I believe that this is a fairly common development requirement, which requires only average skills in database analysis, design, build, test and support. I would be surprised if this requires more than 30 hours at 10 usd per hour, but am happy to receive other quotes.