There are quite a few options that are available, some Z wave, some Zigbee, some WiFi, and some with their own hub and a cloud to cloud integration.
However, they are almost all press to hold, where the longer you press, the brighter light gets.
ROTARY KNOB
- If you want a traditional Rotary dimmer, one choice is the Aurora which is on the official compatibility list. They work fine as an existing switch replacement, so that shouldn’t be an issue.
- In addition, just in March this year several different brands certified zwave plus S2 rotary dimmers. It looks like they all come from the same factory, so I suspect they are rebranded versions of the same device. But they may have someone different firmware and features, I didn’t look into the details yet.
Anyway, the nice thing is these are just multi level lights, I think that should work fine with smartthings as a Zwave dimmer. However, I haven’t seen any reports in the forum yet of people who have actually purchased any. So I don’t know about the build quality or any potential glitches.
The Robb Shop in the Netherlands is a well-established home automation retailer, and they are offering one as their house brand:
https://en.robbshop.nl/z-wave-knob-smartdimmer-robb-smarrt
You should be able to swap out the face plate and cover with pretty much any standard design.
If you do try one of these, let us know how it goes, I’m very curious to hear a real life report. 
(Oh, and note that the same case is being used for a zigbee version. However, my expectation is that that will be much trickier to get to work with smartthings, so the zwave version should be simpler.)
Press and Hold Dimmers
If you want to look at some of the press to hold type, they come in a number of different finishes and styles.
- and 4) Currently Yagusmart and Zemismart are quite popular. Discussion in the following thread. For these, make sure you get the zigbee or Z wave versions, not the Wi-Fi version which is not compatible with SmartThings.
UK Light switches – My experiences (2020)
I personally really like the look of the Yagusmart switches, but everyone has different aesthetics.
- Coolcam were one of the first in this category and have an official integration, but a lot of people don’t like the way there is an LED light ring around the button when the switch is off. So it’s just an aesthetics issue.
- and 7) Historically The most popular option has been the Fibaro or Aeotec in-line micros. These go in the wall and then you can combine them with pretty much any wall switch you like except a rotary dimmer. (The traditional rotary dimmers are analog, and don’t translate well to the digital micros. But you can use a retractive switch for a press to hold.)
Having a neutral available means you don’t have to add a bypass device to these, but otherwise everything is the same.
You will find many discussion threads on these in the forums. The ability to use them with any retractive switches you like which gives a lot of decorator options, but, unfortunately, no rotary dials that I’m aware of.
- TkbHome also makes a line of all in one switches and dimmers which require a neutral wire, so haven’t historically been as popular but can work. You can switch out the face plate covers for other Colours or styles. However, these can be tricky to set up because they rely on zwave associations for some features. And need custom code. So I think fewer and fewer people are using them these days, but you will see some older pre 2018 threads about them and I thought I should mention them for completeness.
- LightwaveRF makes a popular line that requires their own bridge and has an official cloud to cloud integration in the new V3 app. One reason they are popular is that they also offer matching in wall sockets. Also, these offer simultaneous HomeKit compatibility as well, which is a plus for some people.
. Make sure you get the current generation, as the first generation will not integrate with SmartThings.
These come in two finishes, brushed steel or white.
I’m too tired to look up all the individual links for you right now, I will try to update this post later in the day if I feel up to it. But that should be enough to get you started.