What's your budget? Have you considered any other cases? I cannot say I have owned any cases but here's my observations:
The Antec 300 I think would have good cooling, if it was anything like the 900 is. The case is small in comparison to other Mid Tower cases so the air sucked in doesn't have to travel as far to cool components. Also if you have the side fan installed you will have positive airflow, which I prefer. However, the case lacks any cable management, and may require some modding to keep quiet due to the honeycomb mesh causing noise while sucking in air.
The Elite 430 is nice if you're on a tight budget. It's a fairly larger Mid Tower in comparison to the Antec 300, however the fan design I am not particularly fond of. If loaded with fans in the configuration they provide (1 Intake Front, 1 Intake Side, 1 Exhaust Back, 2 Exhaust Top), you'll have negative air pressure and will more than likely accumulate more dust. I also don't like how the front fan is so far away from other components and the case lacks cable management, however it's much better in cable management than the 300.
The BitFenix Shinobi seems to be a better choice out of the two. It offers more fan mounts as well as the best cable management out of the 3. The front fan is still further away from components than the 300, but unlike the 430 you can mount a second fan in the front. Not only that but there's a fan mount on the side and at the bottom of the case on the inside. With most common fan mounting configurations, this case seems like it will have neutral air pressure, which I am still not fond of, but I would rather have that then negative. If you slap in the higher CFM intake fans and lower CFM exhaust fans you should be fine with air pressure.
The Shinobi seems to be the best choice overall when you add more fans, but I would still look around for other cases that you can afford.