I don't use Debian's kernel-source package at all. It's easy to build the kernel using the upstream source and there are instructions in lots of places, including in the source itself (available from ftp.kernel.org or mirrors).
Compiling the Linux kernel is easier than partitioning a disc, configuring X and many other things that Linux users have to do. (Even modifying the kernel is surprisingly easy as the kernel code is so well organised, compared to most code I've seen ...) I recommend you start with 2.2.7 or 2.2.9, though, in order to avoid needing SPARC-specific patches. That's just my opinion. Other people might tell you to use the kernel-source package. Edmund