Which Apache for NicTool?
Either will work fine and if you have a strong preference for one or the other, use it.
Apache 1 notes: Apache will crash, quite rapidly if you compile mod_perl as a DSO and then attempt to use it. This is a known issue and will probably never be fixed. The workaround is to statically compile mod_perl into Apache 1. I have published instructions here: http://www.tnpi.net/internet/www/apache1.shtml. Those instructions seem out-of-date, and they are but substitute the latest published versions and they'll work just fine. If you want a more automated (and up-to-date) approach, download my Mail::Toaster modules and then run "toaster_setup.pl -s apache".
Apache 2 notes: We have a strong preference for Apache 2. It has mostly to due with mod_perl2 and its significant performance and stability enhancements over mod_perl and Apache 1.
However, SOAP::Lite hasn't been updated for quite some time and needs this SOAP::Lite patch to run under mod_perl 2. Apache::DBI is also a bit out of date and needs this Apache::DBI patch. SOAP::Lite has been updated (3/2006) but still does not play nicely with mod_perl 2. Instead, install Apache2::SOAP.
I never have gotten XML/RPC communication to work. However, I have very little experience with it, so if you are savvy with XML/RPC, have at it and submit some patches!