Offline Document Synch

Hi Guys,

I have tried to do some research for a way to be able to view documents offline which are stored in the cloud.

Let me explain better my scenario. I use dropbox to store my most important documents and backups. Lately I have decided to store all Academic-related pdfs in a single folder.
This folder will undoubtedly contain a large number of PDF's very soon which I will need with me all the time on my iPAD.
My iPAD does not have a dedicated Data Connection and I won't always be near a Wi-Fi Spot.
I understand that as far as dropbox is concerned, I need to tick every PDF i want available offline... (which is a bit impossible - i cant stay accessing tens of folders to tick hundreds of pdfs ...)

Is there no solution/app/service that would allow me to select an ENTIRE folder and make it available always offline? (Detecting when there are new changes and immediately download the new files)
I heard of an app named GoodReader that can help but i cannot confirm as i dont have it.

Thanks in advance to all those who reply

*bump*