Hello
Lets see how many I can answer from experience!
An area that size sounds fine to me (if I have worked it out in feet correctly!) I have found that if you can fence part of it off and use it in rotation for when the other area is wet and muddy that would be useful.
Type of chicken is personal choice, I have Orpingtons (good broodies but have patches of not laying) I also have Marans, lovely egg and lay well and some hybrids that lay brilliantly, a couple of light sussex bantanms that also lay very well, Welsummers (which I find a bit fiesty).
We despatch our own and dress them out, the first time we did it we followed the instructions in a smallholder book! We decided to go on a despatch course but to be honest did not learn much more than from the book, just the presentaion of the bird was a little better!
We have for the first time bought in Hubbards for meat, but I dont think I will again, they are programmed to just eat and eat and eat! They are a very good weight but I feel sorry for them, the body seems to outgrowing the feathers and they dont move very far from the food bowl! (they are 5 weeks now)
What you put in thier nesting boxes is a matter of personal choice I think, I have some on straw (because we have it available for the horses) and some on shavings (Orpingtons) because they have a fluffy backside and I have found it is cleaner for them.
As for the electric fence, they will soon learn!
Hope some of that helps