Hello,
I have done something similar in the past, so i can help.
100 times in parallel is doable, but 1,000 or 10,000 could be too much for the server(ddos attack) which can make the website crash or stop responding, or too slow for everyone. I will be able to suggest a safe parallel figure to start with.
I will also integrate proxy support with authentication
It will be a headless cli program,which you can run on linux.
I will also provide the source code
Kindly get in touch so we get started. I'll answer any question you have
regards,
Ben