primefaces - Multiple single selection datatable primefaces

Question

I have a datatable with 2 single selectionmode columns, what i want to do is select a pair of element of my table like this:

So how can I get the 2 selected values from my table?

And if it is possible and u know how to not let the user select the 2 radio buttons in the same row whould be excelent!

Thx to all!