Hi, Stormy123.
This question strictly asks for opinions. I can only share my opinions.
I am guessing that when your company eventually upgrades its Windows Server 2003 machines, they will probably go with Windows Server 2012 R2. It will probably make more sense to go straight to that version so you have the newer certification that
will be valuable longer than the Server 2008 certification.
One advantage of going with the MCSA: Server Infrastructure 2012 is that with just two (2) more exams, you can upgrade to the big MCSE: Server Infrastructure. However, you will have to recertify (probably one recertification exam) after three (3) years
to maintain this title or else it becomes marked "Inactive" on your transcript. As a side note, MCSA titles never require recertification.
If you decide to go with MCSA 2008, then soon afterward your certification becomes less valid after Windows Server 2014/2015 is released. You will have to earn MCSA 2012 or newer soon after anyway. If you get the 2012 version, you can take a break from certification
for a little while.
My opinion - go straight to 2012.
Good luck!
Best wishes, Davin Mickelson