Hi guys, If you had the chance to buy a used 1ds Mk. III in excellent condition, would you buy this over the 5D Mk. II and the 7D? If so, please give reasons on which camera you would choose. This camera has a great price and I will be using this for mostly landscape photos. Also, would you guys use the Canon 300 f/2.8 IS lens with a 1.4x TC for landscape and wildlife photos over the 500 f/4 IS lens? I can afford the 300 but the 500 can be out of my reach.