Good article with a few insights:
/PAE does not do anything for a 64-bit Windows O/S.
Also, the 32-bit address space limit is 4GB, not 2GB.
2^32 = 4294967295
AWE really helps performance on SQL 2000 too.
You might want to think about upgrading to the 64-bit version of SQL 2005, it is why one of my previous employers upgraded to SQL 2005. Depending on your current SQL license, it might not restrict you to 32-bit.