Samba Ver 3.3.14 - AD integration

[Bonface Iregi]

 Dear all,

I am currently working on Microsoft AD project at UN - Kenya.

Their current environment is running Samba ver 3.3.14 and they are not ready to upgrade

The site has two domains; domain A has Samba as PDC
domain B has Windows 2008 r2 as PDC

I need a guide on how to integrate the two domains and if possible ensure users are able to do single sign on.

I came across the Samba ver 4.0 alfa 13 but the client are not ready to go through that route but we need the two domains to communicate.

kindly help

Notes
Current the shared files are running on Domain A
Domino is running on Domain A

requirements: domain will be authenticating users but this will be the final way but meanwhile there is need for two way trust across the two directories

kindly assist in all that i need to do

warm regards,

Boniface Iregi