Is your kernel working at all now or was the error terminal?
The reference to sda is obviously to a disk drive or something emulating a disk drive, like a memory stick. The "s" also means scsi - is your main drive a scsi drive?
Try the command "lspci" to get a listing of what linux thinks is on your box.
I am not a Debian expert and if one replies then you should follow their advice not mine
It would be strange that Debian's kernel builder does not work. Getting that to work is your first priority because it will be the safest option.
You can build and install kernels yourself - it is not that hard but you do need time and care. The basic process is to go to the directory with your kernel sources in then use the command
This create a configuration file.
The command "make" then builds the kernel and saves it in a safe place probably /usr/src/linux/arch/x86/boot/bzImage.
Never go beyond this point without knowing exactly what you are doing because after this we start to change the actual files Linux uses to boot the system.
"make modules-install" builds and installs modules
"make install" then puts the kernel into the boot partition. However, you need a boot loader like Grub or Lilo and to know how that works because you will need to configure it.
You need to read up on all this before doing it because you can end up with a full reinstall if it goes wrong!!
Let me know what lspci said.