Changing the shower head and tub spout : no problem, as these are to an extent "generic" fit...you can find something which will work.
The valve trim is a different matter. If you have a single handle control, your best bet is to see if the manufacturer offers replacement trim for your model in other finishes. If it is a big brand, not too old, there is a possibility here. If it is older or not available, it is possible but very difficult to replace the valve body inside the wall. Generally, I will not undertake this, but there are guys with a little better skills that do this and successfully.
If your shower is 2 or 3 handle, see the above comments about getting updated trim from the OEM. This is your only option. The valve body cannot be changed without a fairly large hole in the tile, and subsequent large chrome trim plate, which some find ugly.
Now, if the OTHER side of the wall from your shower is accessible, such as in a hallway, bedroom, closet,etc. the job can be easily worked from that side without disturbing the tile..and the drywall is easy to patch.