There's two ways to go about this - I tend to maintain a seperate disc of updates made with wsus offline updates and run that right after install to patch things up (which should save the effort of downloading the files each time.Its not automagical or as fast as the other two methods, but its flexible and faster than downloading all the patches one by one.
Otherwise, you can slipstream patches right into an install disk with a tool like rt7lite but apparently you need to use msu files to slipstream into the system which seems like a lot of work
If its always to the same system, you can also simply get a baseline system, patch it, and image it, and simply restore it with a tool of your choice, like clonezilla