What are the versions used by the other developers on the project? If you are a new developer on a project, things like minimum library versions seem like decisions may be the lead architects of the project.
I'm using SuSE 10.3. The program versions seem a little low than I would expect FC6 or FC7 to have. You can search for them on the rpm.pbone.net web site. Filter the results to just find "Fedora Core 7" packages.
You might want to stick to working with the version of php5-gd that comes with Fedora Core 7. If a package is built for Fedora Core 7, but a library version differs, that can cause problems for users. They may have to choose between not installing your package or uninstalling a number of packages that came with FC7. Trying to track down a library version that is significantly more recent than the one used by the latest distro, for a user can be a nightmare. This seems to happen all to often for media type projects. I'll often have to install a late version or cheat with a library link (like I had to do to get kdar working in SuSE 10.3). If you will be using Fedora Core 7, why not install the mysql server and client packaged with Fedora Core 7.
Of course if there have been security updates, the updated version is OK. If you don't need new features of a newer library or program version, the requirements to build a package could be conservative, as your list seems to be. That would let a user of, lets say, FC6 build the package without difficulty.
The only thing I know is that Fedora is Red Hat based system, right!
Yes. Fedora is the Community version of what used to be their RH packaged box set. They sell an enterprise product with support to companies. FC is more of a user distribution. It is more dynamic and will have more versions come out between Red Hat Enterprise versions. Imagine that you install RHEL in a corporation with 30 Servers and 5,000 desktops. You wouldn't want to be upgrading every 4 months.
Come to think of it, I just thought of another criteria on your decision of library and program versions. Is this Open Source project aimed at regular home FC users or Corporate RHEL employees. A CRM suite would be geared for RHEL and so you would probably build it using those versions. what is the most common version of RHEL? Does it's packages correspond to a particular FC distro version. For example, for SuSE's enterprise 10 version, the packages are equivalent to openSUSE 10.1.
Just my 2 cents worth.