yes steve, they can upgrade unis on standard shaft... though price doesnt seem to differ from getting a whole brand new shaft nicely balanced. best option is to supply yoke and diff flange and get whole new shaft i think (best ot provide measurement from end of gearbox output shaft to diff flange mounting face to ensure new one is made to correct length for your setup.

jeff lagerway in knox/ferntree gully vic 97584015

he is very strongly reccomended in many car/4wd modifying circles. i have had him make around 5 shafts just for me