Advice on camera upgrade from Sony S95 to a DSLR interchangeable lens camera

I have had my Sony S95 for over a year now and it has served me well as a compact camera with manual control settings. It's a great camera and versatile to have around but the main issues I have with it is the short 3x optical zoom and the slight blurring which is not noticeable on the camera screen but when viewed on my laptop the photos I thought looked great seem not as impressive in clarity.

I love to travel and I would now like a good DSLR camera that takes impressive landscape and portrait photos. Movie features are less important for me. I enjoy taking long exposure night shots and also photos with good depth of field.

I'm travelling to China, Thailand, Malaysia and Singapore in January so I would love to have a reasonably priced camera to take with me.

Price range £300-£600 and obviously looking for something to compliment my pocketable S95

Cameras I have been extensively searching are Canon 550D, 650D and Nikon D3200, D5100 and D7000.