I would like to point out that EVO has been bought out by P&G, and are pretty much guaranteed to change their recipe to something of lesser quality. Also keep in mind that they have around two months to change the recipe on the bag. Meaning they can have something of poor quality on there, but still have the old recipe up. I would never recommend their products again now.
I can only really recommend some food, since cats in general will be happy with a piece of string or ribbon. XD
Go for anything grain free. Wellness, wellness core, orijen, taste of the wild, etc. are all good brands. I personally like the wellness cat treats, they have barely any ingredients in them.
Wellness Pure Delights® Turkey & Salmon
As for actual food I like Taste of the Wild, but that's just me. Oh! If you wanted to get them some cans of high quality wet food as treats you cannot go wrong with Merrick. Just looking at the ingredients makes me drool, lol.
Merrick Pet Foods - Pet Foods