I meant the tobacco flavor part as a joke, but of course, there are some I can sincerely recommend from where you’re planning to order.
A&L Ryan USA (a balanced, sweet vanilla-caramel mild tobacco flavor), as well as its variations, could be interesting, and for example, Classic Indiana V2 (many people here like this one, it’s a sweet, slightly more characterful tobacco flavor.) 
And if you’ll allow one more remark: check out the buy/sell section, because just yesterday someone posted a Hellvape Dead Rabbit MTL RTA. It’s true it’s not gunmetal, but SS, but it might be interesting for you.
Good luck with the world of DIY building! 