There's a useful nut information chart here that's worth checking out:
http://www.builtlean.com/2013/07/31/calories-nuts-chart/ (It lists the nuts in alphabetical order)
Chestnuts are very high in carbs and very low in fats, cashews are high in both - and though these are some of my favourite buts, I try not to eat too many cashews and avoid chestnuts completely!
I eat walnuts in salads, roast a selection of several different ones (e.g. walnuts, pecans, pine nuts) with sea salt and walnut oil in the microwave to eat for breakfast or supper, and use ground almonds, pecans and hazel nuts (these last two I grind in my coffee grinder) to bake with instead of flour. Hazelnuts with cocoa make good choccie muffins, and I use pecans and ground almonds as the basis for carrot cake type muffins. Ground almonds are really good baking all-rounders.
Flaxseed is also good (in combination with ground alnonds) for baking or sprinkling on stuff .
Mine all come from Tesco, except the flaxseed which I get from Amazon.
Robbity