Privacy and spacious doesn't mean costly. Just get a normal 1 or 2 stories terrace house with a good price/location. Then remove all the unnecessary shapes and portions from the original house design such as un-use tower roofing or wall. Please don't rush but plan it accordingly and make sure every corner have a purpose. For me simplicity is the best. Anyway the most important is you feel comfortable to what you've designed. - Home sweet home.