How much RAM should I buy/How much RAM will my computer be able to use?

Hi. I am working on an After Effects project on a 27-inch iMac, 3.4 GHz Intel Core i7. I am using After Effects CS5.5.

I want to increase my RAM from 4 gigs to either 16 or 32. I understand from an Apple tech support person that my processor can only make use of 16 gigs. Yet someone at crucial.com said that my computer can make use of 32 gigs. Who is correct?

I need a fair amount of processing power for my project. I am stacking up to 12 layers of video, using the beam effect and masks, both of which move around a fair amount. Would you agree that I should get as much RAM as my computer can make use of? (Crucial offers 32 gigs for around $200, so I can afford it.)

Thank you.

PS I understand that if I install non-Apple RAM, I should keep my Apple RAM and switch it in if I have to take my iMac in for servicing, as using non-Apple RAM voids the warranty. I also understand that I have to be careful when installing it, making sure there is no static electricity in the computer. (I may hire someone to do this for me.)

Sareesh, Thank you for the information and the link. I will get 32 gigs. I look forward to checking out your blog. If you have any interest in dance film, I invite you to take a look at the project I am working on. There is a clip from it on my Web site, http://www.cinedancer.com.
Regards,
Victoria