I've seen several questions that I dont think meet the standards met in the FAQ. This question seems particularly low quality to me.
From the FAQ:
what project you should do next
And:
practical, answerable questions based on actual problems that you face
And:
If you can imagine an entire book that answers your question, you’re asking too much.
This question seems like the OP hasn't actually built anything, and is asking what he should do next and he hasn't got far enough to actually encounter a real problem.
The question contains the presupposition that the only alternatives are raw sockets or HTTP. It is not "conceptual".
The requirements describe the main concern of "responsiveness" yet offer no evidence as to why these two particular protocols should have this concern. What does responsiveness even mean? Latency? Throughput? Or an ability to start downloading things before they're uploaded.
The OP states that the files are under 3MB and wants to know if the VPS will have enough memory for N connections. How can anyone answer that?
Do others feel that this question is low quality?
Could this be re-phrased to make it higher quality?
A question of this quality would have been closed on Stack Overflow