Am planing to run a business and i have two option to choose between Magento or Php custom build (both of them will have the same functionality) so am considering about STABILITY and about SECURITY. impatiently waiting for your advice.
Comparing Magento and a custom build is like comparing a program written in C# and another written in assembly. The first option is a HUGE time saver, compared to very few (and often nonexistent benefits).
People have worked countless hours developing the platform functionality, stability and security, which would be very hardly equaled by a custom build.
I would advise you to use Magento and build around it customization based on your needs.