The host is Windows 7 x64
32 bit version of Win2003 guest hangs during boot if more than 4GB of RAM selected (even if PAE is off), kernel debug through serial port shows it break in ntkrpamp.exe (ie NT kernel).
32 bit version of Win2003 R2 guest boots but is very unstable (corrupt files and hangs spontaneously)
32 bit version of Win2008 guest works fine with either PAE on or off.
Tested on VMware Player version 12.1 and 7.1.3
But even if you select less than 4GB of RAM, the setup of latest VMware Tools 10.0.5 crash Win2003 during the HGFS driver install phase. It looks like you do not even test 2003 guests.