Hi Guy,
I may be able to help you re the Marans. I have recently hatched 13, they're due to go out next week, will be ready for sale in a few weeks or can wait for POL if you'd prefer. They're from our own unrelated show quality stock and already are strong good looking birds. I can also supply fertile eggs if you'd prefer to have a go yourself...
Regarding the shed, I've just sourced timber to build my own for a fraction of the price of buying one.
Send me a private message if you're interested and we'll discuss price etc.