I would also say from several sites is better. Neither can hurt, but too many links from only one domain will help less, because it is more likely to be a bought link.
Spread is better IMHO, I think that sitewides are too easily spotted by google. How often do people ACTUALLY link to a site from every page in their site? Never, unless it's paid.
I think having a link on a several different domains with PR5 is more valuable. But the most important thing is to get quality links from value, more authenticate and relevant sites. Higher number of links from worthless or insignificant sites does not add much value.
Well first of all the info you provided was foggy. PR5 could mean a high authority site or could mean a low authority site and that is precisely why we can't use PR. The one domain could have more value and could be more relevant. If you base your strategies on PR you will sink. it is too faulty.
D. Whichever are more relevant to your site's content and have a good link placement with decent traffic. When will people stop obsessing about PageRank. IT'S NOT IMPORTANT!!