Which one should I use, PE, SE, or just Neutrino+gcc

I would like to port my application from QNX 4.2 to Neutrino, and I would
like to purchase the OS and the development tools. I see there are two
versions, Standard and Professional Edition, but I am not sure which one
suit my need. Can anyone tell me the differences? When should I need PE? Can
I upgrade from SE to PE later on? Note that the PE pricing is twice SE. Is
it worth to buy PE now? I am not developing embedded system, but only
realtime control system running on Intel based PC. What I used in QNX 4.2
was just the OS and Watcom compiler and debugger. Do you think Neutrino and
gcc and its debugger will be sufficient? Will SE or PE provide better
debugging tools (or development tools)? I really appreciate any feedback.