I recommend what I use. I've applied the following IDE setup for years under both Fedora (FC5 up through FC8) and Kubuntu (KDE on Ubuntu 8.10 up through 10.4 - current) on both my workstation and laptop. All elements are Open Source. The base IDE installation is Eclipse Standard (I stick to the original, since I started life on the web as a Java developer using the J(2)EE servlet architecture).
http://www.eclipse.org/downloads/
To the base installation, I add the following plug-ins:
Aptana
http://www.aptana.com/docs/index.php/Plugging_Aptana_into_an_existing_Eclipse_configuration
Subclipse (Subversion for Eclipse)
http://subclipse.tigris.org/
PHPEclipse
http://www.phpeclipse.com/wiki/Installation
I use the Eclipse native tools to add and update these plug-ins. That is, Eclipse offers a means to link itself directly to source repositories for plug-ins. A web search for "eclipse install plug-in" will give you BUNCHES of help.
You can run svn (Subversion) for version control locally, if you wish (and don't have access to an external server repository). I have done so previously using the instructions at:
http://nedbatchelder.com/text/quicksvn.html
I only maintain a local svn repository for my own personal projects, since my shop maintains a server-based repository for our commercial projects. Subclipse will hook into either local or remote repositories equally easily.
You can install PHP (or Java or any other Open Source web application language environment you want) and MySQL (or other Open Source RDBMS) servers locally, if you wish. A simple Google-ing for "lamp install opensuse" should give you plenty of resources for downloading and configuring such an installation. Since my shop maintains dev and test environments for PHP and MySQL on one of our (CentOS) servers, I don't bother with a local installation.
Making the shift from a M$ Visual IDE to Eclipse will cost you some startup learning time. The last "Visual" IDE I used was Visual Studio 8 for C/C++. I find Eclipse WAY easier and more sensible than that (slightly an oranges and apples comparison, since VS8 was a fairly ancient app compared to Eclipse). However, there are large numbers of online resources to assist your learning of Eclipse. Yet again, Google is your friend...you are NOT going to have any problems that have not already been solved and posted online somewhere. There are probably textbooks, some quite good, on Eclipse, but I've never used one - hence, I have no recommendation on that point.
I keep the GIMP and KolourPaint apps (Open Source) for image slicing. Since I'm not a graphics designer, I use only the most basic aspects of these programs to edit images for the purpose of tweaking HTML/CSS layout issues. I have known REAL graphics designers who rave about the power of the GIMP, but again - I'm a graphics tyro. I've got graphics gurus who do the heavy lifting at my shop, but they use Windows and Mac tools.
I have developed or contributed to projects from tiny to VERY large in HTML, CSS, JavaScript, Java, and PHP, using this setup. I moved to an Eclipse-based IDE (IBM's Websphere Application Developer - WSAD, later replaced by RAD) back around 2002 during my corporate days. During the last five years of using "pure" Eclipse, I haven't missed the proprietary IBM aspects.