Personally I prefer plastic to metal as it doesn't deteriorate. I use a tange of big boxes from various places - like the clippy ones - but actually the best ones I have currently is a plastic biscuit box, just the right depth for cupcakes.
My square cake tin came for BHS a few Christmases ago - it had biscuits in it briefly, but a nice picture on top rather than pictures of original contents so it doesn't look like a quality street tin, a random lucky find rather than actually searching for one at the time Good luck
I need a large square cake tin to keep cakes in - just one, not a set. Have searched john lewis, lakeland, online - no joy at all! Where else can I look? The only one I found was an overpriced Orla Kiely with a horrible pattern on, surely there is somewhere that sells straightforward tins at a reasonable price..?