Best practice would be to use what the installer natively supports. If it is unattended that works, if it is already an msi even better. If it is a legacy installer or doesn't support silent installations you can re-package it with Wise. I would do a search at
http://kb.altiris.com , You can probably find some best practice documents on there.
Check the samples job folder in the DS. It has two methods:
1)
net use H: \\%DSSERVER%\express
H:
cd \Deploy\SQL\2005\Servers
setup.exe /qb INSTANCENAME=MSSQLSERVER ADDLOCAL=ALL REMOVE=SQL_Documentation SAPWD=password SQLBROWSERACCOUNT="NT AUTHORITY\SYSTEM" SQLACCOUNT="NT AUTHORITY\SYSTEM" AGTACCOUNT="NT AUTHORITY\SYSTEM" ASACCOUNT="NT AUTHORITY\SYSTEM" RSACCOUNT="NT AUTHORITY\SYSTEM"
2)
net use H: \\%DSSERVER%\express
H:
cd \Deploy\SQL\2005\Servers
setup.exe /qb /settings H:\Deploy\SQL\2005\Servers\template.ini