Hey,
If you're looking for advanced practice questions, I have a few options for you:
Advanced GMAT Quant Strategy Supplement - While we don't currently offer an online version, you can pick up the book at one of our centers for free since you're a former course student. We can also ship you the book for free--you'll just need to pay shipping. As far as the advanced verbal book you mentioned, we don't currently have that offering. For advanced verbal practice, try taking a look at our workshops.
Advanced Workshops - We offer a variety of Live Online One Day Workshops, including Advanced Data Sufficiency, Advanced Quant and Advanced Sentence Correction. You can learn more about the workshops here:
http://www.manhattangmat.com/gmat-prepa ... ne-day.cfmChallenge Problem Archive - These questions mimic the most advanced quantitative problems on the GMAT, the types of problems that you will see if you are scoring in the 700+ range. You can find them in your Student Center by clicking the Homework & Practice tab and then clicking on Challenge Problems in the right menu.
I hope this helps. If you have any other questions, feel free to let me know.
Best,
Matt Mapplebeck
Student Services Associate
Manhattan GMAT