Procurement Tool Advice - Contracts Database - PO Tool

Hi All, I am in process of setting up a procurement centre for an organisation who has no procurement function what-so-ever. I am currently looking into different tools we could utilise, in particular a contracts management database and a tool to record, raise and create purchase orders (I have used tools such as Oracle in previous organisations) I was wondering if anyone had any suggestions of effective in-expensive tools that I could look in to? Your help is very much appreciated!! Thanks, Ebony