Hard to visualise without photos. But blackout blinds on the windows with a sheer right across the wall covering both windows looks good. I love shutters also. But agree they are costly but you can get cheaper options now. Even Spotlight does them. A substitute for shutters is a wooden Venetian. Not totally blackout and do collect dust, but they look good. Good luck.

Floor to ceiling, and ideally on a ceiling track. Sheer unpatterned curtains have stayed relevant for a long time now and they can be complemented with a blockout curtain. Provided the ceiling track / curtain system can handle a bit of weight, you can always change the curtain material. Make sure the system itself looks "minimalist".

Another suggestion - sheerview blinds. http://www.bosetti.com.au/index.php/interior-products/sheerview-elegance-blind/ Available from all major blind suppliers. These blinds allow you to control the light totally from sheer to block out; block out 99% UV; available in large range of colours; gives the look of shutters with the softness of sheers all in one neat product.

You will need double tracking or double rods . These will use double brackets which extend out further .If you are on a budget then Spotlight or Bunnings for the rods and Spotlight will have ready made sheers and classic curtains . I have just ordered double rods cut to size from Curtains4Australia and their prices were good . For the curtains and blinds look at BlindsOnline and their huge range . They will send samples of your choice out to you and have a range of fabric prices . If you need help measuring or any questions , then you can ring them and speak to someone who will explain and helping give you options for your window .I have used them for five rooms so far and they are spot on . I will be using them for the rest of my house except for the main sheers as I am after a particular shade and weave . ( I Seek Blinds - I haven’t used them yet ).