Peercoin was the first Proof of Stake coin to be released, and is over two years old. The reward for minting is 1% per year.
PayCoin is something completely different. They claim on their website that they have “Proof of Reserve” backing of USD. This introduces a central point of failure that Peercoin does not have.
The paper you linked to has this quote: “At our planned investment amount, your HashStakers will consistently reach ROI in 2.5 to 4.5 months!” This can only mean severe inflation. Where does the money come from? You. I’m not going to outright say that this is a scam, but it certainly doesn’t look like a good idea to me.