There are others but the REO and Vmod are prolly the most available.
I'd highly recommend the REO grand. I like to put my money on things that are built to last. Once you have one and you want something more exquisite, I'd recommend a pdib OliveR - but the wait for one of those is like over a year out.
I'd hesitate to recommend anything from overseas - sunbox or whatever. The CS on an item like that will be nothing like you'll get from REOsmods or pdib.
Additionally, I need a device that accepts Rebuildable atomizers. The REO accepts Rebuildables but can also run cartos and factory atomizers, if that's your thing.
The vmod - not designed for rebuildables. I've read posts where people have rigged them to run rebuildables but I personally prefer not to have to rig anything.
Here's a short vid I made on the REO grand for those in your position