No, I don't think that you need XP Pro. A bundled Apache-MySql-PHP setup runs just like a normal application, regardless of whether you have XP Pro or Home. This could vary for the different packages, check on their websites before downloading. I have been using Xampplite and it's been running fine for ages.
Also bear in mind that while most of these packages are fine for development work, it's generally accepted that it's not a good idea to run 'live' sites with them. In fact, a lot of the vendors explicitly state that the packages should only be used as a development environment.
Indeed, those tools are targeting test servers; production servers do not run a Windows version. Asides they are the best tools if you want to test any php.ini setup Safe mode etc... If adding (easily done) PHPmyAdmin you can preset your DB, test it and export to production server. You can install on most Wins machines and even upgrade as new packages come around. Further if you do not want to install PHP5 the latest 4 should be available