I need to clarify the difference between no dig for gardening and for growing. I think that misunderstandings arise because I am part gardener, part grower and advise both, so I apologise for any confusion.
On an acre I would not and do not recommend spreading six inches of compost. As you say it would be a huge amaount and there is also question of pathways which are less composted: on a garden scale, cardboard works well for paths, and for growing you could use strips of mypex, but its expensive. I avoid plastic as much as possible with the following exception.
For starting no dig on a large area, especially with lots of couch grass, I would use black polythene to cover and kill weeds, for six months or possibly more if you have lots of couch grass.
I would not aim to grow on the whole area in year 1. However if you need to for economic reasons, spread say two inches compost and grow wide-spaced veg through holes in the plastic, such as cucurbits and brassicas. Weed the holes too.
The first year aim is to clear perennial weeds, totally. Income is lower but money is saved thereafter.
Polytunnels are an eception again. High value cropping makes the six inch nethod worthwhile and I put four inches in pathways too, with cardboard underneath.
See No Dig Vegetables banner for the different options. I suggest two or three inches compost over your weeds, then polythene until May at least. On a smaller area, use the six-inch compost method for early cropping.
I would orient beds up and down. Mainly because its easier to spread compost without it falling downhill onto the path below, and likewise to water/hoe etc in summer.
I look forward to meeting up in February.