[malte]

I guess inserting cartridges from top should be much easier to handle (from user perspective). Some cartridges are quite big, so you must make sure that your components are high enough. Additionally the cartridges can not be pulled in like disks. So you will need a little physical power to get them in. This could be difficult to manage from front. Just my oppinion, should not stop you though.

Maybe you could get some inspiration from retrode. Besides the form factor it seems to do what you want to achieve.