Help finding the right product

Can someone point me in the right direction to get details on where I can find specs/data sheets on this site. I am trying to compare products against one another to make the right decision--this help would be greatly appreciated.

I am trying to find ECG/EKG sensor, oximetry sensor, and an equivalent board. I know once I know how to find and compare products within one of these topics I can do it for the rest.

I have used Arduino in the past for classes but this is my first time using help.

Thought I would post on here while I dig on my own. Seems like an easy question.

Goto products:

Find the product you are interested in and click, eg. for Arduino Due:

You cannot buy that one on anymore, but from China. Under Overview/Tech Specs/Documentation tabs you can find what you need.

Here is nice comparison table: