PS any ideas of what mulch will work?
I would use anything you can get hold of.
Cardboard can be got from bike shops or often supermarkets if you ask. I have used wood chip before and just made sure I sprinkled a nitrogen rich fertiliser like pelleted chicken manure over the soil before the cardboard went down.
My compost mulch is rough old stuff I make from prunings, leaves and woody material like sweetcorn stalks bashed up a bit. I have some white dumpy bags that I layer it up in to rot, with as much green waste as I can spare from the main compost heaps, but it doesn’t have to be perfectly composted to work.