Reply to Foam earplugs?

I know there are varying db ratings on certain types of earplugs, do people buy multiple pairs with different ratings or just use the generic store bought foam earplugs?

I have a gig this weekend on an extremely loud contained system and don't want to blow my hearing....should i just buy the foam earplugs and hope my headphones and booth will be able to be heard through them?

Also, where is the software adjustment for headphones in traktor 2?

I can control the level on my s4 but I know that there is an alternate setting in the software.

Thanks,