LinuxQuestions.org - Setup secure CUPS on network

I have 2 computers running linux, and the occasional windows or mac (and maybe more in the future)...

domainname: quicknix.org
192.168.0.3 - tux
192.168.0.4 - laptop

Both computers have synchronised /etc/passwd, /etc/group and /etc/shadow files, and I have cups installed on them.

My printer is connected to tux, and is set up with cups.

At the moment
tux - cupsd.conf

Code:

ServerName quicknix.org

ServerAdmin root@quicknix.org

DocumentRoot /usr/share/cups/docs



User lp

Group lp

SystemGroup lp



Port 631



<Location />

 Order Deny,Allow

 Allow From All

</Location>



<Location /admin>

 AuthType Basic

 AuthClass System

 Order Deny,Allow

 Allow From All

</Location>



<Location /printers>

 AuthType Basic

</Location>

laptop - cupsd.conf

Code:

ServerName laptop.quicknix.org

ServerAdmin root@quicknix.org

DocumentRoot /usr/share/cups/docs



User lp

Group lp

SystemGroup lp



Port 631



Browsing On

BrowseProtocols CUPS

BrowseAddress 192.168.0.3

BrowseShortNames Yes

BrowseInterval 30

BrowseTimeout 300

BrowsePoll 192.168.0.3:631



<Location />

 Order Deny,Allow

 Allow From All

</Location>



<Location /admin>

 AuthType Basic

 AuthClass System

 Order Deny,Allow

 Allow From All

</Location>

So at the moment, laptop gets a list of printers from tux and uses ipp as far as I know.

All works fine, I can print over the network, but I want to set up user authentication so that I can restrict what users print what. Preferably the user authentication should be transparent for the user. They should be able to just hit print from either computer and it will print using their credentials so I can put in quotas. Also so users can cancel their own jobs if that's possible.

Does anyone know how to do this (using cups or kerberos or anything that may work)?
Preferably I would like it to work with samba also because sometimes I get a windows user on my network, and also so users can cancel their own jobs.

Also my printer occasionally disconnects from my system for no real reason. I think whoever uses my computer might sometimes knock the power cable a bit or something. This is fine, but when it plugs back in, cups doesn't automatically start the printer again.. Is there any way to make it start automatically?

Thanks :D