Batteries are going to be an issue since only brand new ones (on wallstreet G3s anyway) do 3 hours and used ones that still work will likely get you an hour or so.

You can use 2 batteries at a time on a wallstreet.

Wavelan cards are limited in encryption protocol (just WEP and depending on the model wavelan you get no encryption, 64bit or 128bit).

PRAM batteries are pretty much toast by now also (meaning if you remove the battery without the PS being connected it will not turn on again with the battery installed without connecting it to a power brick).

How much were you looking to spend?