Manabush Spiritwalker range doesn't have tobacco flavour and it is excellent. Also have a look at Bunkr. Here is a list of MTL liquid's manufacturers https://www.planetofthevapes.co.uk/forums/index.php?threads/142469/
Primevapes has some excellent custards (shortfalls) but would have to source some stronger nic to achieve 12mg.
For tank recommendations have a look at MTL section of the forum - lots of ideas there. I would recommend Cthullu Hastur Mini - easy to work with and has a good flavour, also readily available. I've heard good things about Steamcrave Glatz Mini but I haven't tried it yet and lots of apes are testing it now as it is pretty new.
I also entertain the idea of not binning the liquids I don't like but giving them away for other apes to try.

 

Have a look at the manabush eggnog, Christmas custard, nut custard, banoffee ect bud. They do a 12mg option.
I usually use 12mg too but have been using 6mg mtl for a while. Opens other options and apart from vaping a tad more I've got on fine.

 

The new range by Manabush do some 12mg options and I can really recommend the Steamcrave glaz mini. Easy to coil and wick and the 5ml extension means less filling, top fill also