Question to those experienced with huge ecommerce Adwords clients

I have the possibility to work on 2 huge Adwords ecommerce projects (around 60k products) with a (more or less) unlimited monthly Adwords budget. I am currently working on a proposal but as I have worked with all type of clients except huge ecommerce clients I am a bit at a loss regarding the time investment for a) campaign setup (the complete range from product to search to display) and b) ongoing management and thus a proper quote.

Does someone has worked on a similar big size ecommerce project and can share his/her experiences?

How are you approaching it?? Will you be using Google PLA (Shopping) Or Search Traffic??

Going to use all of them (shopping ads, search and display). But starting with shopping and display as they can be started quite quickly...the search campaigns on the other hand will take quite a while to set up.