Alsa-driver packages are in the kernels repo http://vectorlinux.osuosl.org/veclinux-6.0/kernels/drivers/
. Gslapt doesn't see it because it's locked out in Gslapt's (slapt-get's) config file, slapt-getrc. At this time, Vector isn't set up for automatic kernel/module updates, thus the lockout.
Sorry not to provide enough info to fix the problem. Falling asleep, but wanted to post at least some info, as it's typically not a good night/time for frequent responses here. Real help will, I'm sure, appear later.