Workflow for a plugin assignment

Question

I'm starting a new project in PHP, a plugin for a website that grabs additional data from it through cURL, getContents etc and re-tabulates it in excel. It's a local project, basic script like with a very limited UI. Iv'e been using Codeigniter and it's a great framework for websites, and even the Twitter application I'm using it for but I don't think I need MVC (necessarily) for this small project but I also don't want to go bare. What would your typical workflow be for this kind of weekend assignment where your creating a local do-something script or like in my case adding functionality to a website? Is there something in between a light weight MVC framework and a blank page?