I'm an associate member of the Knit-Your-Own-Muesli Brigade and have made my own muesli from rolled oats and assorted dried fruits and nuts for many many years. I use Cranberries, Dates, Figs, Apricots, Apple Rings, Pineapple, Mango, Flaked Coconut, Chewy Banana Chips, Brazil Nuts, Hazel Nuts, Walnuts, Cashews, Blanched Almonds, Sunflower Seeds and Pumpkin Seeds. These are chopped or crushed as coarse or as fine as you like and added to the rolled oats in whatever proportion seems appropriate. I eat it uncooked with milk, or with water and powdered milk when camping.
I'm a keen hiker and also use my "source" fruit and nut and seed mix as trail mix or "Gorp". A couple of pinches of it is also jolly nice in plain yoghurt.
You could make up some of the mix and either add to the porridge after cooking for bit of zing, or add during cooking which will result in partially rehydrated and therefore softer fruits.
Incidentally I also include around 10% rolled oats to my bread mix when baking.
Oats is good!