On #3, you can pay someone $6/300 words to get unique content written (and that includes some level of SEO research on the phrases you request). If the quality isn't quite what you'd hoped, use those articles as a starting point and then expand on them, tweak them and reword certain points. Paying more for higher quality pieces is an option too.
Whenever I've done this type of stuff, I've just farmed out my article writing to elance.
Some article writing services do pretty much the same thing, being essentially middlemen rather than having talent inhouse, which is why I don't recommend them, but YMMV
When I found three writers I trialled, it was through elance. Tracked down their portfolios and contacted them off-site. One was in Australia and I believe they outsourced the writing to Asia and the quality (writers who weren't native English speakers) wasn't great. The one I favoured was from the UK. If she was outsourcing, it was to decent writers.
Got a contact who takes a keyword or phrase, does research to extrapolate, writes content pertaining to it, and then delivers it. Can also ghost-write ebooks and the like. Tried three different, cheap writers and her work was better than the other two.
