[LAD] setting a runlevel at the boot prompt?

hi everyone! here's a question for sysadmin type low-latency adepts: i have a general-purpose notebook that doubles as a lean and mean recording machine. it's opensuse, which means it works nicely with most bells and whistles, but it also has an awful lot of questionable stuff running that interferes with stable low-latency performance. so i usually boot into a ll kernel and kill everything i don't need for the duration of a session. to ease that job, i have put the (unused) runlevel 4 back to work: basically i copied rc5.d into rc4.d and ruthlessly deleted everything i don't want. now "sudo telinit 4" will slim down my process list. since the runlevel corresponds with the need for a ll kernel, i wonder: is there any way to tell the kernel (via grub) to tell init to ignore the initdefault in /etc/inittab and go directly to runlevel $FOO? and while we're there, doing a kexec instead of a warm reboot would be so sexy - has anyone played with that yet? tia, jörn