Hi altairahmad,
To answer your immediate question: YES - you CAN schedule an appointment for a Test Center GMAT and for an At-home GMAT, since scheduling one has NO impact on when you can schedule the other (you could even schedule them for the same day - although that would NOT be a good idea). However, both attempts would count towards your 5 Exams in a 12-month period 'limit' and 8 lifetime attempts.
There have been several points during this year in which you were thinking about taking the Official GMAT. Have you taken either version of the GMAT yet (and if you did, then how did you score?)?
GMAT assassins aren't born, they're made,
Rich