I would like to get it from you if possible. i maintain my own distro and have already compiled gcc and glibc for 2.6.21.5 and for compatability its just eaiser.
Your kernel has little to do with gcc and glibc.
The kernelheaders used for compiling applications which glibc depends upon have been seperated from the kernel sources ages ago. They were seperated exactly for the reasons you mention.
I suggest you use the latest kernel (2.6.22.x) due to some bugfixes in the kernel.