In that case, I'd simply hand over the necessary install for my required elements.
It's just that for many people that I end up working with (in mid-size business enterprises), getting a web server up and running turns out to be a project. Being able to install custom perl modules, another project. Setting up a custom application on that web server, a third project. If I can get them to a point where they can experience the software and see value quickly then I've gotten through two barriers that otherwise would have taken a great deal of time and effort to get past. Of course, I could have a demo up and running on the web, but if I can get it on their desktops where they can see what it's like with their data in their environment, I might actually be able to sell something.
I could have them install xampp, install some gnu utils, then go about installing my software - and that might actually be the preferred path for some people. I'm more looking at trying to help less technical people get to a starting point with as little pain and effort as possible.
It may be preferable to just wrap the installs of all the necesary software in a batch file or install script that calls them individually - but still the question exists - is it OK to redistribute, and is it OK to make changes to the default implementation as part of the redistribution.
I know there's a lot of repackaging/re-selling of open source products like openoffice and I don't want to come off like I'm doing that kind of thing. I want to do it right, give credit where credit is due, follow the licensing requirements, and not be in violation of any community standards that are not formally communicated. (In, I suppose, a similar manner in which apache friends has done with XAMPP)