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
Peter
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.