Mid-2009 13" Macbook Pro HD Upgrade...

Original SATA was 1.5gbps, SATA2 is 3.0gbps, and SATA3 is 6gbps. Your machine is SATA2, though a SATA3 drive should work, as they step down to accomodate the slower speeds. 7200 RPM is faster for loading, etc., but it does run hotter. An SSD is the optimal choice, as it's MUCH faster and has no moving parts. A nice compromise is the Seagate hybrid drive. It combines a standard drive with some SSD technology. Not as fast as a true SSD, but much cheaper.

http://www.amazon.com/Seagate-Solid-Hybrid-2-5-Inch-ST1000LM014/dp/B00B99JUBQ/re f=sr_1_1?ie=UTF8&qid=1395054011&sr=8-1&keywords=seagate+hybrid

And here's an enclosure:

http://www.amazon.com/Sabrent-2-5-Inch-Aluminum-Enclosure-EC-TB4P/dp/B005EIGUD4/ ref=sr_1_3?ie=UTF8&qid=1395054074&sr=8-3&keywords=2.5+enclosure

Either are good. I think Apple uses Hitachi themselves. If I were you I'd consider the Seagate pretty strongly. Like I said, it's not a full SSD but it does speed things up. I can tell you that my mid-2010 is way faster to boot than one of the current 13" classic models. An SSD makes it feel better than a new machine. If you've got the money to spend, take a look at the Crucial SSD's on Amazon.

That was one question? lol

I can tell you what I did on mine. I have a 500GB Crucial SSD and a WD 1TB hard drive. I used the Data Double from OWC to replace the optical drive. That's pretty easy. As you can tell, I'm a fan of the Crucial drives. Mine has just worked flawlessly from the start. I had an Intel first, and that was a disaster. If you click this link, you can look at the various sizes and costs.

http://www.amazon.com/Crucial-2-5-Inch-adapter-Internal-CT240M500SSD1/dp/B00BQ8R M1A/ref=sr_1_2?ie=UTF8&qid=1395093872&sr=8-2&keywords=crucial+ssd

I don't think the Seagate hybrid would be a bad choice as the data drive either. One thing I do is to keep a copy of the OS on my hard drive, just in case something goes wrong. You can just start with the Seagate too, to keep the costs down. Bear in mind that by the time you buy a smaller SSD, the Data Doubler, and a 1TB hd, you're not far away from a big SSD.

That cable isn't cheap, so I wouldn't buy it until you see a problem. Your research was good though. Sometimes the SATA cable is marginal, and when an SSD replaces the HD, the added demand kills it. It's not all of them by any means though, so I'd hold off.

http://www.ifixit.com/Guide/MacBook+Pro+13-Inch+Unibody+Mid+2009+Hard+Drive+Cabl e+Replacement/1340

Do you know how to copy your old drive to the new one? The easiest way is with an external enclosure and Carbon Copy Cloner. You put your new drive in the enclosure and clone it. Then when you swap the drives your new one looks exactly like your old one. Super Duper is another option, but it doesn't clone the Recovery partition. The external enclosure can then be used for your old hard drive, which gives you an external to use for backup or copies of important stuff.

http://www.amazon.com/Sabrent-2-5-Inch-Aluminum-Enclosure-EC-TB4P/dp/B005EIGUD4/ ref=sr_1_3?ie=UTF8&qid=1395098054&sr=8-3&keywords=2.5+enclosure

By the way... much cheaper price than ifixit...

http://www.amazon.com/Drive-Cable-Sensor-MacBook-Unibody/dp/B004VSZCL4