I actually did that once for a bay window in my living room. Rather than using sash rods, I used dowels and tubing. It worked OK! I have since decide that I like the treatment on the outside front of the window, so abandoned the homemade rod, but it DID work!

I think it sounds like a great idea. Make sure they give you that 3/4" lift or you'll be cutting it close with the handle. You could also just get a different handle which doesn't need as much clearance. Most Bay Windows are secured to the house with a cable system that hooks to the top rail of the house (if close enough) or wall studs somewhere above the window. In most cases we tie into the existing soffit. If we have a cable support system we try to screw the cable locks to the top rail for the best support. Since your adding an extra 200+ pounds you may want to make sure the cables will cover the extra load. If not, make sure they install some gussets under the seat board to carry the extra load. I would also recommend your installers lifting the outside portion of the window a 1/4" above level. I personally go a 1/2" over to allow for the stretching of the cable. It will usually drop any where from 1/4' - 3/4" ounce the cables settle in. I'd make sure your Bay has a higher exterior side than the inside to make sure any water from the sink doesn't run down and puddle next to the window. It would be much better to have the water run back in to the sink. Have them raise it just enough to let the water move away from the exterior side of the Bay. Most of them have adjustment nuts on the bottom to correct after everything has settled. Also make sure the seat board in the Bay unit is insulated. I don't know what climate your in but the granite top may conduct cold and heat from the seatboard of the Bay unit and cause some issues down the road. So check and make sure this won't be a problem later. Otherwise Good Luck!!!

We have one now and will be putting in another when we move the kitchen in the near future. Ours is 4" above the counters and 18" deep. We like it because it lets sunlight in the room for a longer period of time during the day. The new one will be south facing, so we're getting light throughout the day and can maximize cabinets on the west facing walls (the east walls will be interior). That being said, it does collect dust. I keep my unnecessary kitchen decor up there to look pretty while not getting in the way. Of course, that stuff collects dust as well. I also made a valance that hangs about 10" with beaded balls that look pretty in the light. I lined it in an interesting stripe that looks pretty from outside as well. My husband is almost 6'4", so he has window cleaning duty. I take the fifth when it comes to how often we clean windows. We have a step stool. We do not go mental when things are not 100% spotless. I'll clean up the space in the existing window and try to figure out how to post a picture for you later today.

First off you have beautiful home and congratulation on your new home. I'd suggest going to the floor if you're going to go with curtains on these window and if you're okay with going above the picture rail i'd suggest that. Going above the rail will just add height to your room. 1/4'' is going to be too narrow to do an inside mount. If you like the idea of having some of your trim show you can always mount on your trim, but just don't cover it all. Honeycomb and roller shades would be good pairing options with curtains. A roller shade will project out farther than a honeycomb shade.... just something to consider. If you're open to suggestions on an alternative option consider an Illusion shade. They have a modern look and give you versatility with light and privacy. The illusion shades are beautiful on their own or look nice with panels as well.