IMHO Proxxon are massively overpriced and deeply underperforming tools. Suitable for small /toy stuff/ model ships etc. I say this having owned their mill and mini table saw. They look flashy, but that is all. The 400 is a badged version of a seig C1 only not as good value
The 180 is a much more robust machine and generic to most other Chinese minilathes
If you will only ever want to make small parts for model ships /dolls houses/ toy railways / or possibly clock parts then buy the 180, because come the day you wish to expand your horizons, you will wish you had if you don’t.
If you want a more flexible stronger machine to start with, then get the 180 and give the bird to the Proxxon.
That is your choice.