That is a difficult one, if you are out of the loop for even a few months you can lose track very easily.
All of what I am going to say is purely opinion based.
But the TFV8 is hands down the best sub ohm tank you can get.
The TFV12 is out now, but that is just overkill.
I recommend you buy a TFV8.
Furthermore check out
fasttech.com for the greatest deals ever, not enough people know about this great site.
A lot of what you see online is all opinion based and it's up to you what device and box mod you choose.
p.s. For a box mod I would recommend the RX200 (Or a Kbox 200W for something a little smaller)
Furthermore, check these out:
Best Sub Ohm Tanks of 2017 - Vaping Insider
Best Rebuildable Atomizers 2017 | Top RDAs and RTAs
(They are opinion based like everything, and not necessarily the best sub ohm tanks like they state)