Shutters sound like they would be a great addition to your new almost at the beach house. Is it an open concept? If so while you can change things up a bit you'll want to repeat some element and ensure that everything looks great together. Even the rooms you're thinking of putting drapes in might benefit from shutters or wood blinds for both looks and light/privacy control. Also be aware of how these windows will look from the outside. When choosing fabrics look at your existing furniture for inspiration or a piece of existing art or if buying new furniture think about the windows as you do. Everything in the room ties into each other. Ideally you would have swatches and samples of every finish in the room from flooring to window coverings and everything in between including wall colour, area rugs, bedding ect to help make your final decisions easier.

Try the TV where the sofa is now and float the sofa perpendicular to the fireplace where you currently have the big chair. Perhaps the big chair can then go where the TV was for a quiet spot for one. Or even better, pull the loveseat off the wall and put the big chair to its left flanking the fireplace.

How come you don't want to go with the two lounges in the room if it works out okay?

I have no idea where you could get that from. Maybe try Amazon.