The other choice is AWS Bedrock, if it happens to have the model you're interested in. They do have GLM-5.3. They don't have DS-4 or 4.1 yet, and updates are intermittent at best, but they're already on the trusted provider list for anywhere large enough to be interesting.
Yeah, about that... My kid works for a very small company. Chatted the other day about in-house inference vs ZDR providers and all. His team is trying to get access to GLM on AWS Bedrock. It is a second week they are trying to schedule a simple meeting to discuss what they need. Random silence, and back and forth from a new person each time. 2 WEEKS to just schedule a meeting... And as far as I know, no luck so far.
That may not be acceptable for many companies outside of the USA.