As far as I know, bees wax, cocoa butter and shea butter are the way forward....
for more products with these ingredients, try http://www.letsgetsoapy.co.uk
I made a scrub before using coarse granulated brown sugar and almond oil... it lasted ages and smelled yummy! As long as the oil is covering the sugar I think it is ok!
http://www.letsgetsoapy.co.uk for amazing bath and shower products
I don't know how to make Lotion Bars, but I do know that http://www.letsgetsoapy.co.uk does massage bars that are full of essential oils, cocoa and shea butter and bees wax
I have heard that Kukui Oil is very good for the skin and skin problems, it can be mixed with baby lotions etc and can help clear up eczema...!
This website sells it at a good price too: http://www.letsgetsoapy.co.uk