Typically we follow an Agile development process that tends not to put an emphasis on writing requirements and technical documents that nobody will read. We tend to focus our limited manpower to development and testing activities with collaborative design and whiteboarding as a key focus.

There is a mostly standalone web component that will take quite a few weeks to develop, but this work can be mostly parallel with other project work going on. To try and catch up time I was given a budget for hiring a developer on oDesk to complete this work.

While my team isn't accustomed to working off of a firm SRS document, I realize that with outsourced development that it is a good idea to be as firm and specific as possible so I realize that I need to provide a detailed Requirements and Technical Specification document for this work to be done correctly.

When I do write a Requirements document I typically utilize the standard IEEE SRS document template but I think this is too verbose and probably overkill for what I need to communicate to a developer. Is there another requirements document that is more lightweight and also accepted by a major standards organization like the IEEE?

Further, as what will be developed as a software module that will interact with other software modules, my requirements really need to delve into technical specifications for things to work correctly. In this scenario does it make sense to merge technical and requirements specifications into a single document, and if not, what is a viable alternative?