I'm pretty sure libapreq2 is still in beta. If you want the most complete working version of it and Apache::Request, you'll need to get the latest sources from the CPAN. But in all likelihood these later versions depend on more recent versions of mod_perl2 itself, largely because they may depend on some mod_perl functions that were unimplemented in earlier versions. So you may have to install that from source as well

In terms of production code, if you're stuck I would say either stay with Apache 1.3 or else use CGI.pm or CGI::Simple instead of Apache::Request. They're slower but much more likely to work.