The style of table you have selected will directly impact on which chairs will work. For example, you'll often find that circular tables can accommodate far wider seats and even high backs will work well, wheres more angular designs often require compact chairs, as they'll have legs to contend with.
If you have one formal and one casual dining space, you can really go to town with different chair designs for both. A casual spot will do best with sociable, comfy seating that naturally leads to conversation, whereas a formal setting is where you can play around with luxury fabrics. If you only have one dining room, you're going to need to combine all of these elements in one set of chairs, if possible!