Congrats on buying XRP. It was only a matter of time it will run up to $1. I missed that train so hard. About your decision, I would definitely go for Cardano. They are actually a platform and backed by computer science and scientist. They take everything the original blockchain is missing and make it even better. I am about to move on Cardano myself, and believe me, I will hodl for a long time.

If you want to dip your toes into cryptocurrency that is the perfect plan. BTC is known for the wild rollercoaster rides from ATH and retracement of close to 40%. But buying every months 25 a time you will definitely have a better average and you'll definitely won't risk as much all at once. BTC will eventually keep rising and never die it. When everyone talks about cryptocurrency the first things people think of his BTC, so it is the best sound investment. Like the other user stated, use gdax because there are no fees for deposit, withdrawals and trades.

My picks for Janurary 2018 is SysCoin. Syscoin is rebranding by the end of this month with the help of some advertising and marketing company. In addition, they are introducing masternode setup and the web version of their block market early mid-February. Expect a lot of interest in the few days before the rebrand and web block market release. Again, do your own research before you invest.

To me honestly, a correction will happen soon. For a coin to have a healthy organic growth a pullback is necessary or a consolidation period before another uptrend. If you look at 2017, ETH has been up like 30X already so its pretty much at its peak. So yes a definite correction soon, just wait for it.

HODL this coin if you can. With 250 ETH I would be jumping up and joy at the moment. It just passed $700 today. Continue holding because eventually, ETH will take over BTC spot in my opinion. I know it's tempting to sell as it breaks new ATH, just think of the potential gains you will have in the future. BTC was once $900 this year and it went up to $19000.

Those are really some nice rigs that everyone put up. But back to the original post, although your rig layout looks great you might want to spend a bit more money on a professional rig frame. I wouldn't try to save a penny here or there because you need to think about the repercussions of cheap wood---causing fire--- and bare metal ---electrical shorts. Take it from me, I spent about $30 on woods and screw and after 3 months --- luckily I was home --- the excessive heat on one of the GPU started sparking out and literally sparked and started smoking on the rig.  Spend a bit more on peace of mind.

Like most of the post here stated, it's hard to get another 100x or even 1000x coin unless you get it at pre ICO price and a platform coin. When Ether came out it was like .50cent during the ICO stages and smart contracts was a new technology in the crypto world. I guess what I am trying to say is find a new coin with a new platform, not a fork of a coin, but has a new tech that is new to the crypto world. Look into ADA, LISK and EOS they are still cheap and they are platform coins. I, myself, have diversified on these 3 coins because I know newer ICO will use these coins as a platform. Again, invest in the tech, not in the hype.