Welcome! I’m sure you’ll get lots of suggestions, and of course different things will work for different people depending on budget, aesthetic preferences, etc.
I’ll start out with just a few thoughts, in no particular order.
- smartthings currently supports 3 protocols locally: zwave, zigbee, and thread. Plus a handful of LAN devices that have special integrations like Hue and Sonos.
However, there’s really good news on the horizon: once the new industrywide matter standard is fully developed, we should see a whole bunch of new inexpensive Wi-Fi and thread devices that will communicate locally with a smartthings/Aeotec hub, and will not require any special code to do so. There will also be more thread devices in this category.
For this reason, my own suggestion to my friends right now is to wait for four or five months before you start shopping for devices unless you really have to get something now. You’re probably going to have more choices at lower cost and with easier integrations. True, there are no guarantees until we actually see what gets made available, but the trajectory looks good. I’m putting off my own device purchases right now for this reason. But of course it’s your choice.
- if you do decide not to wait, I think the least expensive reliable options for the EU that work with edge drivers right now are probably the devices from Shelly. These are WiFi, but as long as you set up a separate server device, you can communicate with them locally. They have a lot of different device types, good safety certifications, and are quite inexpensive. They may not have matter compatibility in the future, that’s not clear yet, but if you’re only going to run them with your smartthings account that won’t matter. (They also have a cloud to cloud integration,p which won’t require any custom code or a local server device, but my understanding is that you prefer stuff to run locally.)
Here’s the company website. Make sure you change the country to your own so you see the correct device selection available to you.
Shelly - Shelly
And here’s the forum thread on that local integration, I mentioned:
Edge Shelly device support discussion
- my personal recommendation is not to get anything from tuya at this time. These are sold under many different brand names, but they will all use the “smart life” app. And probably have the Tuya logo on the device picture.
Yes, they are very cheap, and yes, they have very cool features, but they are designed to work with their own hubs, and they use a lot of proprietary code, which is a pain to get to work with any other platform, including smartthings.
Once matter is fully deployed you will probably be able to buy an inexpensive tuya hub of a model that works as a “matter bridge”, connect your Tuya devices to that, add that Tuya hub to your smartthings account, and have it bring many of its devices with it without requiring any custom code. That will be very cool, and should be pretty easy and more reliable. But we aren’t there yet.
I’d say about a quarter of the posts in this forum in any given week are from people who bought a tuya device and can’t figure out how to get it to work with their smartthings account. 
. If that extra work and research doesn’t bother you, there are certainly a lot of people buying them, it’s just not my personal recommendation.
- and before we go too far, please be sure you understand that, even with edge drivers, smartthings is still largely a cloud-based system. Edge drivers means that more things run locally, but not that everything runs without the Internet. The hub expects to connect to the Internet most of the time, and the smartthings app only works if your hub is connected to the Internet, even if both your phone and hub are connected to the same local Wi-Fi. So if your interest in edge is because your Internet is not reliable, smartthings is probably not a good choice for you. There are several other competitor systems which can run well without an Internet connection after initial set up, including hubitat, Homeseer, vera, Apple HomeKit, etc. But smartthings is not one of those.
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I think that’s all I want to write right now so as not to get too overwhelming. I’m sure there are lots of other people who will have other suggestions. I’m going to tag @Mariano_Colmenarejo in case he wants to add anything since he lives in the EU, and is the author of many of the most popular custom edge drivers. 
