Speed and parallel requests are not a requirement in my case

But you want parallelism, and the three options I mentioned provide that. And there are again, plus a fourth:

• System threads + <Any web client, incl LWP::UserAgent, Net::Curl::Easy, etc>
  Creating threads in Perl is heavy and can cause problems.
• User threads aka coroutines + LWP::Protocol::AnyEvent::http + LWP::UserAgent
  Requires async-friendly code.
• Net::Curl::Multi
  Uses select-able file handles to indicate when it needs to be called. Could also poll.
• AnyEvent::HTTP
  Calls callbacks or sets cond vars on completion. Requires async-friendly code.

You didn't say what you are doing in parallel. You didn't say what event loop you are using. So it's hard to evaluate which option will work and which is best. Provide more information, and we can provide a more detailed answer.