Mine just eat a hamster and gerbil mix, they will also take rat pellets and love millet spray and monkey nuts!
I haven't really tried a lot in the way of treats or fresh foods such as fruit or veg as i haven't really researched them in that area, but they've done great on my above diet, males can get a little weighty, so peanuts, sunflower seeds and other fatty foods may need to be kept stricly as treats to prevent chunky monkeys
When I had african pygmy dormice they used to enjoy some orlux insect pate and waxworms. Wonder if spinies would eat things like that too? Shame you are so far Naomi, my local feed place sells aubiose, it's what I bed my rats on.