I also have a 2018 and I decided to go with Lasfit for my LED conversion. They were very easy to install and work great. The only thing to note is that the LED headlights have a fan on the back to cool the metal components and the dust caps didn't fit back over the DRL/High beams. They did fit well on the low beams however. I went with the H15+H7 package and the difference is huge.
Heres a link for them: 2014-2019 Mercedes Benz CLA250 Custom H7 LED Bulbs Exterior Interior Lights Plug n Play
I bought a 2018 model 6 months ago. I would have obviously optioned LED if I had built myself as I love MB DRLs. My car has every option aside from disctronic and LED and had miles/year I wanted for a great deal so I purchased it. Like I said the difference between halogen and LED is huge so its worth upgrading for safety reasons.