So Many BW modes to choose from.....

I know alot of ya'll recommed BW. So many models in their list.
Can someone help me fine tune which one...

50 Gallon with good/great recovery.
Max height 5'

Traditional Vent - Natural Venting
Gas
So if I buy a direct vent unit, supposedly it's more efficient than standard venting ?


Model DS150S6FBN
Anything else ya'll need to know

I'd consider one of those that qualify for the Federal energy credit http://bradfordwhite.com/tax_credit/certification_statement.asp.