First, SATA is many times faster then IDE, there is no debate about that.
The fastest IDE speed is 150MBs. The slowest SATA speed is 1.5GBs(1500MBs), and the fastest so far is 3GBs(3000MBs). There quite simply is no compitition.
And then add in the little fact that most SATA connections have RAID options, which will double the proformance if you use it.

And you can never have too much air-flow. Get the fan.
Just one thing, make sure that the air flow goes in the front, out the back. If you just randomly put fans it, it won't be very effective. You want to get the air pushed in one direction, and the direction with the best effect is in the front, and out the back.