Hi djoking,
Most GMATers have full-time jobs and busy lives AND find enough time to properly study for the GMAT - so you do NOT need to quit your job and pursue your studies 'full time.' As you've already realized, having a 'hole' in your Work History can be a potential issue when it comes to applying. In addition, the type of heavy study that you're considering can greatly increase your chances of 'burning out' before you even get to take the Official Exam (and that burnout is something that we want to avoid).
Since it sounds like you're just beginning your studies, then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can take 2 for free at
www.mba.com (and they come with some additional practice materials). If you want to do a little studying first, so that you can familiarize yourself with the basic content and question types, then that's okay - but you shouldn't wait too long to take that initial CAT. That score will give us a good sense of your natural strengths and weaknesses and will help provide a basis for comparison as you continue to study. A FULL CAT takes about 3.5 hours to complete, so make sure that you've set aside enough time to take it in one sitting. Once you have those scores, you should report back here and we can come up with a study plan.
I'd like to know a bit more about your timeline and goals:
1) What is your goal score?
2) When are you planning to take the GMAT?
3) When are you planning to apply to Business School?
GMAT assassins aren't born, they're made,
Rich