3rd Attempt in the Making - Need Feedback/Advice

I started my GMAT study journey back in September 2009. I signed up for MGMAT online self study course and took my first GMAT exam in late Dec 2009. After failing to meet my target of high 600s, reaching 700 mark, I took some time off to reassess and reflect and started the preparation again in February 2010. I took my second exam a week ago and devastatingly only went up 20 points since December. I work in consulting and my hours vary, travel demands vary - part of me thinks I just don't study enough, or perhaps not effectively.

Actual GMAT scores:
Dec score: 590 Q36/V34
May score: 610 Q43/V31

My practice scores before my May exam from GMAC were:
GMAC3 710 Q40/V47
GMAC4 710 Q49/V38
GMAC5 720 Q49/V40

Materials covered:
MGMAT SC, all of Quant Strategy Guides
OG 12th Edition (all of Quant & SC)
OG Verbal (only SC)
OG Quant
Grammar Book

I believe my issue is not preparing for CR and RC in verbal but I can't be sure. I have a ~70-80% accuracy during practice exams but perhaps on the real exam I fell short. I can't say for sure since during real GMAT score reporting, there is no breakdown available to confirm or deny this belief. I'd like to take it a 3rd time and hopefully hit my target by end of August as I am interested in applying in 1st rounds (October).

Some options I am considering for this time around preparation:
Study and employ the strategies/methods in MGMAT RC and CR Strategy guides.
Do the RC and CR questions in OG 12th & OG Verbal, not limit doing those problems just during practice tests.
After reviewing all my SC materials and notes, buying PowerScore SC for more practice (~70 accuracy in SC from an initial ~30 accuracy)
Keep up with Quant by reviewing/re-doing problems in OG 12th/Quant, MGMAT Strategy Guides

Perhaps going further...
Should I sign up with a MGMAT Private tutor? I can't meet the individual in person since I am not located in one of branch cities, it would be conducted through webconferencing. Anyone have experiences with private GMAT tutors they can share? Were they effective and worth the money?

Any insight you guys can provide to help me get back on my feet and tackle the GMAT successfully a 3rd time would be greatly appreciated. Verbal is really problematic for me but my Quant didn't quite reach what I expected either. How much time do I still need to spend to get to where I need to be (Is late August a realistic timeline given my circumstance?) Advice, questions for me to think about to further analyze my performance/study methods/weakness + strengths in Quant and Verbal would be GREATLY APPRECIATED!!!