ddgonzal,
Not sure why Hilux (Toyota G-series) has the wrong stud pattern? aren't 2WD hilux 5x114.3? and 4WD 6x???. BW78 is either 4x114.3 (R31) and other 5x??? axles.

As for decision:
Either way you go the machining work is about the same and nullifies that as a discriminating factor. Although.... It is possible to machine just one BW78 axle to shorten for a 1200. But given you are tubbing with presumably big offset wheels, you will need to shorten both sides.

Everyone can pick up either BW78 (Falcon, Commodore Nissan R31) or a Toyota G series (Land cruiser Prado, Hilux, Hiace, 4 runner etc) for next to nothing, neither come with the right spring perch offset or 4 Link bar offset.
Look at the axle strength option, G series has bigger, thicker axles standard (30 v 28 spline).
The G series is an 8" ring gear, I think BW78 is 7.8" (I think). Not going to worry you.
G series would probably be heavier overall.
Ratios will be important for your application. If you need taller then 3.5:1, you will struggle to get with a G series setup (Very hard to find). short gears are the opposite, harder to get in the BW78, heaps in the G series due to the 4WD range it was brought out in.
LSDs- Stock both are very crap for anything other then mild street and drag racing, on a circuit track both standard diff will not cut the mustard on a mild track worthy car. BW78 has a cone style LSD (Happy to be corrected on this) where as the G series has preloaded clutch plates.
If you go aftermarket LSDs, options available for both. Cusco/Kaaz, Torson, Lokers, Spools etc.
Ratio changes are arguably easier with a G series as the third member is removable, where as the BW78 are attached to the housing. Although the majority of people would not change ratios very often.

Whilst I have a preference for my application, I have tried to keep my bias out of the above detail, it is really up to you both have their advantages.
There are other options too, early Mazda's (with the right aftermarket upgrades can be good), ford 9" or 8" cheaper replacement parts, arguably overkill.