What we did for these bedroom windows was move to a standard "L" frame and designed it to work as an inside mount. All other specifications remained the same. But, additional standardization was required as the window frames were not square. So, our master installer needed to provide fill and chalking to cover the uneven light gaps on the side. When he was done the customer commented, "I can't even tell that this needed to be caulked."
Shutters are always a great option for any remodel as they are timeless and tend to hold their value over time.
Of course, we would love to help you with your shutter project. Also, check out our online shutter cost calculator for a rough idea of what new shutters might cost.