If you're interested purely in price appreciation then a MinexCoin investment could be an interesting one. This coin is one that is not really intended to be used as anything except as a cryptocurrency. They also offer an interesting feature that allows investors to "park" their investment to earn interest.
This is different than a proof of stake model, where you are essentially competing for blocks like a miner, in this set up you will always be paid your percentage, and the randomized factor is removed. Read on for the further explanation of this under the radar asset.
It's possible for you to buy MinexCoin on only a couple of smaller exchanges. This can be both a bad and a good thing for a potential investment. If a coin is restricted to a smaller volume exchange the price could be below its potential, however, if it does not get on to a larger exchange for a long time you could be waiting quite a while for any price appreciation due to this as well. Bitcoin is the highest volume trading pair, but there is some liquidity in ETH as well.
As for storing your currency, they have a downloadable wallet version for Windows, Mac, and Linux. If you prefer a mobile solution they also have some attractive mobile app options available as well for Android, iOS, and a web wallet application.