How to modify the size of the Feature Content Image

I would be interested to have pictures in vertical instead of horizontal and if there is a possibility to have more than 4 Feature Contents per line? My site: http://home-kare.es/wp/ I've checked we can have more than 4 images in total but I want to show the first page of golf, home, etc.. catalogues and they are in vertical. Obviously if it's possible to get them in vertical I could have more on a line. Thanks in advance for your reply. Best regards. Alain