Here's a sour cream to start: http://paleotable.com/2012/11/paleo-sour-cream/. For whipped cream, I just use the coconut cream mentioned earlier in this thread. Once you make your own mayonaise, any creamy dressing can be made. Mel has some good ones: http://www.theclothesmakethegirl.co...recipes/sauces/

Google is your friend when looking for substitute recipes. Just type in Paleo Whatever and a number of recipes will pop up to consider.
I am always amazed how many new Paleo Recipe websites appear each day.
Yesterday, I stumbled on a beautiful one following a Biscuit link:
http://zenbellyblog.com/2013/03/21/rainy-day-biscuits/
I'm in awe of the time and talent people have to create beautifully photographed websites...and happily gather up the free tips.