OldFrog, would it work if I tried to run your script on my 64-bit machine after I upgrade? If so I can try to make the 64-bit packages.
Of course it should, but just think it will fail several time until you ionstall all the needed devel packages. I must say I install my new boxes as developement ones, and I just need a couple pcakages (as libcryptopp-devel, libgeoip-devel).
Actually, my spec file is 
hereJust store it somewhere, go into the same directory and run the following script:
#!/bin/bash
RACINE=/home/Fourbi/aMule/cvs
DIRBUILD=/usr/src/rpm/SOURCES
DIRRPM=/usr/src/rpm/RPMS/i586
echo [$1]
if [ "$1" == "" ];then
export  datum=`date +%Y''%m''%d`
else
export  datum=$1
fi
who='whoami'
  cd $RACINE
  if [ -r "$DIRBUILD/aMule-CVS-$datum.tar.bz2" ];then
    echo "File exists - will not download the file again^^"
  else
    if [ "/usr/bin/wget" ];then
      echo "Using wget for getting the tar file"
      wget http://www.hirnriss.net/files/cvs/aMule-CVS-$datum.tar.bz2
      mv $RACINE/aMule-CVS-$datum.tar.bz2 $DIRBUILD
    fi
  fi
  if [ -r "$DIRBUILD/aMule-CVS-$datum.tar.bz2" ];then
    echo "Building RPM"
    rpmbuild -bb --clean $RACINE/aMule-CVS.spec
    if [ -r $DIRRPM/aMule-CVS-$datum-mdv8.i586.rpm ];then
    echo "installing RPM"
         urpme aMule-CVS
         urpmi $DIRRPM/aMule-CVS-$datum-mdv8.i586.rpm
    fi
  fi
This script downloads the current tarball, builds it, then installs it replacing the previous one. At the end, at a time I added tghe ftp to upload somewhere, but I prefer not to do it anymore, due to then DADVSI law in France, 
Just adapt the three first lines to your needs
RACINE is the place where the spec file is stored
DIRBUILD is the place where you'll store your sources (Mine is the default one, don't vha,ge it u,less you know what you do)
DIRRPM is the place where the rpm will be stored. Mine sis the default one for 32bits, I don't know what it should be for 64b, something like  /usr/src/rpm/RPMS/XXXX
Hope this helps.