oscommerce search optimize (Sphinx install)

We heavy a very huge osccommerce webshop and because of this search not work very well. We want this to be optimized, perhaps install Sphinx into the server to optimze the search. Another very annoying issue is that we got a lot of double orders. Perhaps because of server load, or just a php thingy, i do not know, but we want that fixed for good. Also need advice to get MySQL synchronized on another system, and perhaps use a separate file-system for the images. We got several servers available for that option. Only bid if you are professional and ready to fix instead of investigate.