Sydney Transmission recommedation who wont destroy car, ZF5HP24

1999 X308 Sovereign LWB, concourse condition. 240,000km V8.
Sadly freinds , the car has lost the reverse gear, so i did a complete transmssion oil change of 10 liters by myself, in one go, and now the car drives better in forward gears , but reverse is still gone when hot. When cold, reverse is ok.
Imo , its the Sun Shaft gear bushings that have worn out, causing oil to seep through when warm. Now with even the transmission additive i added this time around i dont see the new clean oil decreasing the seepage compared to the old think dirty oil.
Are there any recommendations for a ZF transmission shop in Sydney Australia that will do a good rebuild and NOT DESTROY the rest of the car, … someone who will actually replace all the bolts, torque them right, redo the exhaust system right etc?..and actually rebuild the trany properly.

all recomendations appreciated.
best regards
sydney Australia

Unfortunately I don’t live in Sydney, but there are only two avenues for the ZF trans.
No. 1, a BMW specialist, because all BM’s use a ZF trans. or No. 2. Jag specialist.
If you were in Melbourne, I could send you to my friends BMW shop, who I made all the special service tools for.
But get Quotes from both, but remember they will only be a good guess.