Is it possible to compile native GCC for ARM (host == target == ARM) using Code Sourcery G++? If it is not possible, could I use crosstool-NG to build the cross-compile and
CodeSourcery provides prebuilt toolchains only for Linux/x86 and Windows (see "Host System Requirements" here). If you want a native ARM-hosted toolchain, you should be able to build one using a cross-compiler. If you want a prebuilt one, you can try some of the existing ARM distros such as Debian-arm, or Aboriginal Linux (it's made to be run in QEMU but you can probably extract the compiler from it and run natively).
Tiny C Compiler runs decently natively on the kindle 3. Find it on the mobileread forums compiled for native use.
Code sourcery toolchain works for simple comilation via "arm-none-linux-gnueabi-gcc foo.c" IIRC with no effort. creating native arms. Crosstools-ng as well but neither natively AIUI.
I looked into http://buildroot.uclibc.org/downloads/manual/manual.html#_about_buildroot for a more comprehensive solution.
There are some options in there for what you require IIRC using x-compile to make the compiler but Crosstools is the more robust chain I had trouble with codesourcery doing true static build. HTH
better off to use openembedded