I think you've just learnt the hard way that you reap what you sow when it comes to car maintenance (or lack of).
Do some searches and you'll find loads of stuff about cooling. Several months of reading!
Also, have a look at:
http://www.bmwe34.net/E34main/Mainte...eplacement.htm
and the rest of that site as there's lots of excellent information.
For the tranny, give Kurt Keller a call - a search should find his details (if I've spelt his name correctly - you might need to insert an 'o' somewhere into his surname).
Good luck.