Well you don't have a lot of room. The top might work. Or the same around, like your moulding.

What didn't you like about what the carpenter was doing originally?

Are you planning on window treatments? Honestly, you only have room for shades; Roman, roller, blinds, etc - no curtains.

Def do not very the size of the trim - needs to be the same on all four sides otherwise will look awkward.

I would suggest using a simple trim the same size on all four sides. I also suggest a drape using a light sheer material or a luminette, either in a very light color-cream or white. I don't think that the trim will be quite an issue once you have a window treatment in place. Good luck on your project.

I agree w/ 2 above. Window moulding on sides &top have to be same b/c they meet at corners. That style is very common & not purely colonial. They can't be wider or will get into mantel on left. Below sill could be wider b/c sill separates it from above but wider would get into wallplate below. Crown's fine, too. You're going to love windows. We replaced aluminum windows w/ doubled glazed abt 4 yrs. ago. Not only save energy, much, much quieter.

Keep trim consistent on all sides and choose a moulding that matches or comes close to what's on the other windows in that part of the house.

I once worked for the "cheapest renovator in the city" who pulled half of his materials from dumpsters for use in rental houses owned by cheapskates, resulting in each room having different trim profiles and sizes, among other things. It looked awful to those born outside of trailer parks.