Great to hear your thoughts on this, and happy that they are in the same directions that i was thinking, too. I have an old pressed steel shelving that I think I could use with magnet strips and this will probably be my first port of call. I'm taking some time to think about how to mark it up to get things happening consistently... and wonder about magnets moving the base around as i peel them up. I might end up weighting it a bit to make it more solid.
And Walter, that also very good input, and the answer is that I will almost certainly want to change the aspect ratio and size of my prints... flexibility is needed, no doubt!
I've just picked up an old 6x6 folding camera that will produce negatives that match the enlarger, so hoping that i can learn to utilise the square frame while shooting and print square, too.
Thanks again gents, I will report back