I'd suggust emailing the companies... Sometimes they will send you free samples or coupons... Natura (EVO parent company) did not send me any when I contacted them, but wellness (CORE I think) did send me samples of regular wellness, so might send some of CORE if you email. Not sure about "taste of the wild". BUT Orijen is made in Canada, so if you're there they might be able to send you a sample (I emailed them and they replied that due to boarder crossing into the US couldn't send any samples of food to me).
I'm feeding mine EVO dry but I also highly suggest the EVO 95% meat canned foods. My cats love the chicken/turkey and beef. The dog cans are the same as the cat cans, so sometimes you can get them a bit cheaper if labeled as dog food.
I have had good luck with the dry EVO, but it is very heavy in calories, so if your kitty has a weight problem be very careful with how much you feed. Some folks report very bad gas and stinky poo... My kittens are ocassionally gassy, but I haven't experienced the severe problems that some do with EVO. I believe most folks also suggest feeding a combo. of wet and dry when feeding a grain free dry to make it easier on them to digest it. I DO know that my kitties tend to drink more water than they did before.
One last tip, check out the protien,fat, fiber, and moisture content of each grain free... Some grain frees can be just as carb heavy as a non-grain free (they just use potato instead of grain). The less protien, fat, fiber, and moisture it has, the more carbs it will have (which most companies conveniently leave off the label).