Information regarding gcc

[A, Sravanthi]

Paul/Team,

We have our API programs defined in C++. Now we are porting from Solaris
5.8 version to LINUX. Currently I am using gcc 3.2.3 on Red hat 3
server. But iam getting some many errors like " ISO C++ says that
`TYPE&" , " conversion from `int' to `std::_Ios_Openmode'".  From below
link understand some issue with 3.2.3 compiler and requires more code
changes. Iam afraid that we need to reconstruct code. We have Red Hat 4
server also but with different update versions.
http://gcc.gnu.org/ml/gcc/2004-07/msg01011.html 

Could you please confirm below?
1.Which version of Red Hat server and gcc combination  to be used when
porting from Solaris to LINUX. 
2.I was browsing sites to know tips and precautions while porting. Any
special actions to be taken for thread handling when poting? 
3.Let me know if you have any predefined document.

Thanks
Sravanthi