What is the best source of GNAT for Win32?

["Steve" <nospam_steved94@comcast.net>]

I have been using the distributions:

  gnat-3.15p-nt.exe
  gnatwin-3.15p-nt.exe

Which I downloaded from cs.nyu.edu when they were new.

I see that gcc-ada-3.4.2-20040916-1.tar.gz is available from mingw.org.

Questions:
  Should I consider using this new version?
  Is this the only thing I need to install, or do I need 
gcc-core-3.4.2-20040915-1.tar.gz as well?
  What do I use in place of the gnatwin package?
  The original distributions had nice installers that set everything up for 
me, how do I go about setting up the new environment?

The thing that raised the question for me is the new release of GPS (which 
is the first version I have successfully been able to use).  The project 
wizard likes to insert directives that gnat 3.15p doesn't know how to 
handle.  I can just delete them from the project file, but it would be nice 
to not have to.

Steve
(The Duck)