If you really need "real-time-ness" TSDB will probably not work.
You could go with sparkstreaming or flink but for that amount that will be overkill. Kafka scales quite nicely and is relativly easy to operate (compared to spark etc). But thats only if you really need to scale, for your current usage even kafka is a bit overkill.
just to clarify does that mean you should already have a work permit, or eligible to apply for the common visa's? I would expect the first but i couldn’t find any clear definition in the past since it changed from case to case