Hi,

In my opinion (and it's my opinion only) that you really need BOTH. I
buy both every year and, while there is inevitably some duplication,
for the most part the books complement each other rather than including
redundant information.

They're both rather dog-eared at the end of the year!

I know that's not the answer you wanted, but, as I said above, that's
my opinion.

Right now the cheapest (and easiest) place to buy them is Amazon.com.
If you do buy them both together, there will be no shipping charge.

Best,

Joe