I have the official SL disk with me, but it was bought about a year ago and there have been many updates since. Is there anywhere to download full 10.6 instead of using the disk and manually downloading and installing the updates?
In short, there is no place to download an updated disk unless you went the "WAREZ" route... and I won't name the typical places those are available.
Now, if you want to make one yourself, it's possible... but time consuming.
Take a look at INSTADMG, and using that tool you can create a up to date baseline clone image, in a few hours, via a fully automated system.
(I use it to create images for our clone deployment)
Now, this isn't exactly what your asking for, but it's the closest that is perfectly legal, without going out and spending money.
The next best thing is to purchase an updated DVD (I believe they are shipping 10.6.3 or 10.6.4 disks), and use that... But you'll still have to update the system with Software update after it's been installed from there...