Materials. Look for bathroom basins made from quality materials. You don't want anything that will be easily damaged. Scratches can make it look old and dingy so get something that is highly resistant to scratching. This will keep it looking like new for years to come and you will appreciate the way it prolongs the value of your investment.
For the sanitary ware go with wall-hung or standard close-coupled toilet and basin with pedestal with acute angles and a contemporary design. Abstract towel rails and wenge wall-hung furniture fit well in the fantasy bathroom, giving it that calm almost surreal look.
Pay Attention to Size. If you plan to use the same insert location where it already is, you will need to shop for bathroom basins that fit that same size. You will also need to get one that is the same shape. Some are square or oval while most of them are round. If you want to completely change it up, you can go with a different size and shape.