I use my old check boxes from a TimageList, I like fancy looking Xes and checkmarks ,.,.,.
But one issue to consider is the option to adjust the hot spot for the check area so that it can be read for drawing code to work around it there for saving it for your checkmark drawing. also this area information should be in a property as a Rect for instance so that it can be adjusted initially if the default position and size is not desirable .