I'm not real up to speed on niceties of the forums yet and hope I'm not necroing this thread, but I'd strongly advise going with real-time game play with pausing like Baldur's Gate or Dragon Age: Origins (like other people have mentioned in this thread). I personally prefer turn-based game play, but it can be a lot harder to code. With real-time action with pausing you have more standard player controls, AI code, etc. and there are eleventy skidillion Unity resources out there for those, but with turn-based you'll need to spend a lot of time and effort on more complex game managers, worry more about timing events correctly, and more complex pathfinding depending on if you decide to use classic tile-based nodes. If you do some searches you'll see a lot of questions about coding a turn-based game with Unity but not many realistic or usable answers.
The above is just my $0.02 and not intended to discourage you, but is based on my experiences and will hopefully help you and your team make good decisions considering what your skill levels are compared to your overall theme and game design. Good luck!
MrSkyhenge
P.S. I mocked up a turn-based prototype last Thanksgiving using standard Navmesh and coroutines to manage unit and actor states...if you want I could dig that up, comment the code better, and make a Unitypackage for you to review to see if you could use it for something. It ain't no thing would just take a day or two...just let me know.