the ifs hub spacer on a SA makes the wms wider from the inside of the hub i guess, the bolton spacer makes it wider from the regular wms... you could do both and be a huge amount wider
BUT I THINK IF YOU ARE GOING TO RUN THAT BIG OF A TIRE YOU NEED TO GO WITH FULLSIZE FULLWIDTH AXLES!!!!!
Toyota axles are strong, but I don't think you can make them 44x18.5-19.5 strong --- or what gearing you would use to move those....