Ditch the LPG idea. Will set you back way too much for a capable LPG system ($10k area). There's a guy on here rarely and often on AFF, GAZ084 who has done a supercharged BA xr6. Spent big $$$ on the LPG and ended up going to a factory petrol tank setup all with aftermarket options xr6ts use. To save the $$$ is go bf mk2 xr6t. There's no such thing as a 1 tonne falcon they were all dealer options that may have included uprated leaf springs. But I wouldn't want to be throwing weight in an xr ute, they have a max payload of 440kg setup as factory. Also keep in mind most alloy trays weigh around 100kg depending on extras. The tub body weighs more so will aid in traction.