I'm relatively new like yourself and been doing a lot of research to check my efficiency and how to profit the most.
From what I can tell is that the core clock doesn't actually affect your hashrate as much as the mem clock does. In fact the bios I have loaded onto my 480 reduces core clock and power and increases the timings. Head over to TechPowerUp and check what they suggest is the optimal for the 1060's you've got and check the memory make on the boards before you do.
As for the dodgy Riser. I've read many threads on these as well. It does seem like build quality is not that amazing on the cheaper cards so get decent ones basically.
For the Coin, it could be anything in the future. Some are suggesting dual mining with zcash, or sticking with eth and watching the difficulty and price to make an educated guess on whats most profitable. If you would rather fire and forget then maybe nicehash is the way to go where you rent out your hash power to them and they'll mine whats best and pay you in BTC.
So mining Solo at 10/12mhs will be very slow on getting an income, as you'll only see a balance when you actually mine a block. At that rate you'll get approx 1 a year.
However the setup so far is right. You've got the progs running and now its a case of efficiency and hashrate. Mining is a lot about getting a comfortable balance between power and hashrate.
To increase your hashrate you can overclock the memory on your GPU. If you fee; brave then you can mod the actual bios on the card as well to reduce power and increase the overclock to give better returns. Modding also brings in more considerations with memory manufacturers.
Once you're happy with that, then just duplicate that with a many GPU's as you can. Hoewever it's best to start with the GPU you intend on using so you're not doing the work twice.
Check out the Education discussions to see what issues people are running into and have a good long think about your project before you invest anything.