I'm on my second GM diesel.
2 batteries is standard and I don't think you can get dual alternators. When I tried configuring options on the GM website, as soon as Duramax is selected, dual alternators become unselectable.
On my GMC I had the rear window defroster, which I used a lot in winter. The Chevy has sliding rear window, so defroster can't be ordered. This will be the first winter without rear defrost, so time will tell if it is a good thing or not.
Get good tires installed right from the get go. The GMC came with Bridgestone or Firestone tires and they were useless in snow. Put Michelin LTX MS2 on and drove through deeper snow in 2wd than the others could handle in 4wd.
Heated seats are nice!!!!!! :B
Never considered rear camera either, but new truck had it. It makes it real easy to line up trailer hitch on the first try. No good for your 5th wheel but if you pull utility trailers it may be handy.
good luck in your choices.
Brian
