Hey mate!
1. I don't want to make the viking suspicious, but yeah it's a solid choice for that build -- I'd definitely go with the mini and not the nano though unless you want to invest in a drip tip insulator. The cloupor goes as low as 0.45, so it can handle both the 0.5 & 1.2ohm coils for the subtank, and most are running the subtank at or well below 25w.
2. Keep an eye on that Cloupor Mini, they're having some real issues right now with them catching on fire and not just when charging.
Do listen to the viking and check out various reviews though. The other option in that category is the Delta II which has gotten good reviews, but I've avoided due to its whistle.