Mama,
FWIW-
I believe that you can use SuperDuper to replicate your G5 to your laptop, but there is no need to first install 10.4.6 on the laptop as the OSs need not be the same. So I vote for option # 3.
Also, using SD over networks can be tricky, so I suggest connecting (directly) the G5 and laptop with a firewire cable.
In this case, and for the first “copy”, I recommend using SD’s option: "Erase (Laptop) then copy files from (G5)". From then on, a Smart Copy should be fine and much, much faster.
And finally, when all is done, a run of DiskWarrior on the laptop is suggested.
HTH