I'm pretty sure the reason Crichton went with frog DNA is to work in the sex-change angle for the plot, so life "could find a way" and thwart our hubris.
Jack Horner's plan to create dinosaurs involves chickens. Even though they're far from the most "dinosaur-like" bird, they're common, cheap, and caring for them is pretty trivial.
If none of you have seen his talk on creating a dinosaur, it's on Youtube. I went to the same talk when he came to my local university, sponsored by our geology department, since I hang out with dozens of geology students. Speaking of that, my suggestion for the best potential place to find intact dinosaur DNA is a blind valley (a bowl) down in Antarctica, where glacial action wouldn't have ground everything into the ocean and ice would've just sat there. By boring down to the bottom of such a valley with an ice-melting device, and then melting along horizontally, perhaps scientists could find relatively intact (but squashed) frozen ancient organisms.
Even as a sci-fi plot it would be better than a mosquito, combining Jurassic Park with The Thing.