Hi malcolm123,
Before you spend a lot of money, time and effort on that type of service, it would help if you could provide a bit more information on how you've been studying and your goals. It might be that what you're asking about - and what you actually 'need' - are not the same thing.
Studies:
1) How long have you studied?
2) What study materials have you used so far?
3) How have you scored on EACH of your CATs (including the Quant and Verbal Scaled Scores for EACH)?
Goals:
4) What is your goal score?
5) When are you planning to take the GMAT?
6) When are you planning to apply to Business School?
7) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich