50W, so you like a DTL vape I take it? In which case you're probably going to need something airy. Many are better suited to MTL/RDL but there are a few that can do DTL too.
A lot of people speak highly of the Voltrove 1.1, and the new Reload Ammo seems like it would be really well suited for DTL too. Neither are cheap though.
Cheaper DTL options would be the Damn Vape Atemporal or the Kylin M boro (this is mesh though, and whilst it is great it's limited in capacity).
The new Meson boro from Steam Crave comes with a coil deck and mesh deck.
@Mutley1 got it recently as part of the kit and seems to really like it.
All of the above come as part of a bridge/tank combo.
Some more to look into:
The SXK Mobb 2 clone from Ecigone. You will need a boro tank for that though. The largest air pin is 4mm and from my experience I'd say it sits on the line between RDL and DTL.
The Suicide Mods Ether, this has a 4mm pin and comes with a tank you can use any bridge in. A few folk on here have them so hopefully they can chime in.
The Cthulhu 850 which has a 3.8mm air pin and also comes with a tank you can use other bridges in.
That's all I can think of for now but I'm sure other members will have some suggestions for you, and you could always have a look through this thread:
https://www.planetofthevapes.co.uk/...s/what-build-do-you-have-in-your-boro.211531/
As for cotton and coils, again different people will give different answer but I like Cotton Gods cotton and Coilology pre made coils. I usually buy 2.5mm Fused or Tri-Core Claptons. Some bridges can take 3mm coils, but I find it's pushing it a bit on the ones I use.