SEO tools ~ Expert advice needed

Hello all.
I own about ten niche sites which give me a decent ppc income.
I used to outsource the link building, but it revealed to be expensive on the long run.
Right now, I need some good tools to improve my business.
1- A rank tracker. I had SEO Power Suite Rank Tracker but now the search algos updates expired and I do not want to pay a monthly fee. So I need a powerful tool (one time fee payment) that creates reports, has a scheduler and (if possible, not necessary) can send emails. There are a lot of wp plugins, which is better between a desktop software and a plugin? Can you recommend me one of them?
2- I have to keep my rankings at the top of the SEs. I know the best way to do this is by steadily creating high quality backlinks (I'm talking of drip feed). I know a little bit of link building but I don't know which kind of backlinks work best to mantain SERP position - I'd prefer white hat strategies... Are blog comments enough?
Secondly, I do not know if I have to chose a all-in-one solution (such as Ultimate Demon) or task-specific tools. No monthly fee products here please.

Last but not least, I read somewhere that Incansoft products are useful and quite cheap. Do you use them?

Thank you Warriors!


P.S.lease note that I have already read a lot of threads, but I didn't find anything for my case.