Making a Support suite needs some info.

As you are writing in PHP, you don't have much of a choice with the whole source-viewable thing unless you keep the source code in-house. In other words, using it for your own projects or as a hosted solution.

If not, go open source. You can chose to have a more collaborative stye source code writing, or write it all yourself and provide the release in increments. Just be sure to test, and don't be surprised if other people use parts (or all) of your code in ways which you don't necessarily like.

Chose GPL if you want other people who do this to release that code as GNU as well. If you don't mind the idea of people making money off their projects using some of your code, you can chose a less restrictive license like MIT or BSD.

Remember, also, just because people are making money off of it, does not necessarily mean they are violating the GPL. What is important is what license they have released their projects with. As far as I know, I believe you may take a GPL project and create a hosted solution and charge people. But you cannot take the code and release it under a different license. And as always, you must attribute to the original code/author.

I believe that info on licenses is correct, but remember, the law and license agreements are open to interpretation and it's best to consult with a lawyer or such before making any big decisions.

Call me unimaginative, but I can't really imagine features for support software beyond tickets, chats, forums and wikis. Depending on what the support system is actually for, you can maybe build some sort of easy sandboxing for support admins to automatically execute common tasks.

Bloated software is annoying. It is best to consider your average user as a person with the intelligence and attention span of a 5th grader who refuses to take his Ritalin. People tend to like clean interfaces, with nice color schemes, large fonts and cute graphics. Oh and don't forget the smilies.

Also, take a look at your competition. As far as support suites go, I have seen many many companies pay $30 a month to Kayako. They may be raking in it for sure! But I am also sure they have a large team of developers, testers, marketers, and of course people who search the web looking for people who violate their license agreement.

Good luck to you.