The Uwell crown is a great choice (I base that from what I hear about it, I am a MTL vaper.) I really can't give too much feedback on tanks other than that one.
As far as a mod to pair it with, I'd suggest a two battery external battery mod (and you'll need a charger, to buy the right batteries from an authentic source). For more on that go here:
https://www.e-cigarette-forum.com/blogs/mooch.256958/
https://www.e-cigarette-forum.com/blog-entry/baditudes-blogs.7609/
As far as two battery mods, I have a few l like (despite my puny MTL-ness). The Steampunk nano, it only goes to 120 watts, but it's a two battery door. Early reports of issues with the battery door although they appear to have fixed it fairly inexpensive.
The Smoant Cylon (Smoant makes some other really great mods, too. Vaperesso isn't a bad maker at all for the price either. It's not heavy. The Eleaf invoke is tiny, and super small form factor, and pretty durable despite it's size, I've dropped it many times. An Innoken mod (they're really nice and durable and reasonably priced) and lots of offerings there, too. Finally if you are looking for durability, a Geekvape Ages (it's a one battery mod, but you may wind up preferring it if you are hard on mods and out and about a lot.) I have a Geekvape Legend which is the "two battery" version of the ages.. It is certainly durable but also quite LARGE, some folks would have a hard time carting it around all day (I'd say that about the Steampunk nano too, it's all metal and it is heavy.) With that said, Teslacigs, who manufactures the Steampunk has a lot of other offerings in a variety of style and options including the Wye which I think is plastic, and lighter.
Best of luck,
Anna