Buying a ML server in Germany

I have a project which requires training 3-4 conversational AIs based on the dialogpt-medium model.

I am not concerned about the training being extremely fast, as long as it doesn’t take more than 1.5 days to train each model.

What is more important for me is to use the same machine as a server for 3-4 instances of these trained dialoGPT models at the same time for long periods of time. So half training, half server - I’ve never built a PC before so I’m not completely sure on the distinction or implications, or different requirements.

I’m in Berlin, Germany currently. Can anyone point me to a machine or build list that would be suitable?
I’d prefer not to sink endless cash into a cloud service.
I’m happy to spend €3-4k.
Thanks for your advice!