Im looking for somthing that can belong to many many models and, hopfully, has all the resizing functionality built in too.
Wondering if there's any good suggestions out there, I don't want to pick the wrong one.
Or is it just worth building my own?
I wrote a pretty sweet image upload component a few years ago for Cake 1. I don't have a clue where the code is these days, but my friend Koa did a write up on it a while back:
http://labs.iamkoa.net/2007/10/23/image-upload-component-cakephp/
http://labs.iamkoa.net/2007/11/06/multiple-image-uploads-into-single-mysql-table-cakephp/
Might be something you can hack. It handles uploads, resizing (resize, crop, resize then crop, max, mix) and if I remember correctly, it might even do filters (flipping, inverse, greyscale).
I also ported the code to Zend framework (and PEAR file naming) for my new content management framework. It's all contained and much better now (does all the things I mentioned above and is pretty well documented). You can download that here (check out the ImageManipulator class. I think the FileUploader class has a dependency on my String utils class which you could easily remove if you want to use that.
Otherwise, I say roll your own. The component architecture in Cake was confusing to me at first so it could be a good learning XP if you don't know it yet. If you do, you can just grab someones uploader and convert it into a component for your Cake application.