I have found that the instant vanilla flavor works best. Using other flavors I found the cookies to be a bit dry. If you want a chocolate flavor dough I would add a bit of cocoa to the mixture.
I prefer salted nuts as they add a nice dimension to the finished product. I use macadamia nuts for their unique flavor and crunch, but pecans are very tasty also.
I love dried cranberries in this recipe, however, I did make them one time with dried cherries and they were delicious! Feel free to exchange the craisins for cherries or apricots or whatever floats your boat !
The chips can be semi-sweet, milk chocolate or white chocolate - it's all a matter of preference.