How to build GNU toolchain for AMD64?

[khapi]

I'm using a Linux distro that doesn't have a 64-bit
version, and after trying two that do (Ubuntu and
Fedora) and seeing how incompatible they are
with my hardware, I've decided to take a minimalist
approach and build the toolchain and kernel myself.
However, I've run into snags, and the information
on the Web seems fragmented and dispersed.

Binutils seem to build without problems:

mkdir /opt64
tar zxfv binutils-2.18.tar.gz
cd binutils-2.18
./configure --prefix=/opt64 --target=x86_64-pc-linux-gnu
make
make install

However gcc builds only the first stage and
at the end of that, it complains that it cannot
create the binary, seemingly because it doesn't
know the name for it (gcc).

export CFLAGS='-Dinhibit_libc'
export PATH=/opt64/bin:$PATH
tar jxfv gcc-4.3.1.tar.bz2
cd gcc-4.3.1
./configure --prefix=/opt64 --target=x86_64-pc-linux-gnu --enable-
languages=c --disable-shared --disable-multilib --enable-
threads=single --build=x86_64-pc-linux-gnu
make

Can anyone assist?
Thanks.