Exam Preparation - Experiences and Advice

Hey Folks,

I'm looking to revamp an exam preparation tool we have had for a couple of years.  Currently we have a bank of 600 questions in a Quizmaker file.  Users engaging with multiple questions, thus larger suspend data (we are using SCORM 2004 V4), or what seems like going between Flash and HTML5 have proven to be some obstacles to making this a great tool for our learners in preparing for a certification exam.  At times the progress is not kept, while other times the Quizmaker visual correct and incorrect marks are lost on subsequent starts and resumes even when using an Exit button.  It's intermittent at best, but in no event when a learner answers more than 50 questions is the progress and thus visual markers saved on subsequent attempts.

Our goal is to create an exam preparation tool that provides the following:

1. Users want to practice the exam and real time see which ones they got correct and incorrect (preferrably in the navigation bar like Quizmaker does).
2. We want the bank of questions to be 600 or more questions.
3. We would like to use Articulate's suite of products and SCORM to accomplish this so that the results of learners attempts are stored and we generate analytics on questions that learners got correct and incorrect.
4. The learner can reset the exam tool at anytime.

We are open to using other tools.  Does anyone have any suggestions on approaching this, or other tools they've used for something similar that might not have the issues around exiting and resuming, large data suspend rates, and the rest?  We want to provide learners with an exceptional experience as they complete the practice exam and are able to use the results to continue studying and/or resetting without running into  issues with losing progress?