I need some advice on what airsoft AEG to purchase. I'm a Newbie so bear with me. Model Preference: M4 Carbine Budget: 300$ max Where you play: Small Fields, most targets will be within 75 - 150 feet (occasionally up to 200). I've been looking at M4s, like these: http://www.evike.com/products/36986/ - I like this one and was thinking about upgrading the spring and body. http://www.evike.com/products/34490/ http://www.evike.com/products/42571/ http://www.evike.com/products/41853/ Any alternative suggestions to these would be great, especially if they also have flip up sights. I also have a few questions. 1. What would be a good FPS for the range I specified above? 2. Should the body of your AEG be metal? Is there a huge difference in durability between plastic and metal bodies? 3. If yes (to the above), would it be better to buy an AEG with a plastic receiver then buy a metal receiver to replace it? Thanks for the help!