my suggestion is to redesign reporting database to fit reporting specifics (e.g. brake normal form of database, in some cases this will speed up reports). Than you can use some ETL tool to sync production and reporting. Good thing is to use some OLAP software to use multidimensional analyze - this will make queries easier (with MDX language). I think this kind of discussion is huge one :)
there are some opensource ETL and BI suits available.
