PLEASE HELP me select new internal hard drive for Macbook Pro 2012 (non-retina)

Question

Good afternoon.
I just bought a Macbook Pro 2012 (non-retina) 15 inch from a friend.  I think it is running Mountain Lion (has not been upgraded to Mavericks yet), and has iLife on it.  It came with the stock 500 gb 5400 rpm internal hard drive.  At home, I only have the Snow Leopard OS installation Cds and a copy of iLife 2011 installation Cds.  I am going to buy 16 gb of RAM from Other World Computing to install.
I want to replace the hard drive with a 1 tb hard drive, preferably something that is $100 or less.
I talked to Other World Computing (OWC) and looked at the Data Doubler Option to replace the optical drive with a Solid State drive, but decided that for now I want to keep the optical drive inside the computer for portability issues.
I know that Solid State drives are better, but they are still too small, and I want the ease and portability of a 1 tb size INSIDE my computer.
Initially I was going to order this from Other World Computing: 1.0TB 2.5" HGST Travelstar 7K1000 7200RPM SATA 6Gb/s 9.5mm Notebook Drive 32MB Cache. *'New' Factory Replacement with 2+ Year HGST Warranty*    As of April 4, 2014 it's on sale for $79
But then I started reading some of the discussions online and thought maybe I should get a hybrid solid state drive?
I saw on Amazon the Seagate 1TB Solid State Hybrid Drive SATA 6Gbps 64MB Cache 2.5-Inch ST1000LM014  It's on sale for $94.
But according to some reviews, this Seagate has a platter that is only 5400rpm, unlike the previous Seagate Momentum that has a platter speed of 7200rpm.
How reliable are the Seagate, versus a Toshiba or Western Digital or Hitachi or something else?
Here are my questions about replacing the hard drive:
1.  Is a hybrid solid state drive going to need some kind of special formatting after I put it into the macbook so that I can put the operating system on it?
2.  Is a "normal" platter hard drive more reliable than a hybrid solid state drive?
3.  Is there any additional driver or special software that I have to install for a hybrid solid state drive?
4.  Currently there is no personal data stored on the computer.  Can I just put the new hard drive in, and then insert the snow leopard install cd?
5.  If I install snow leopard, can I just go to the App store and get the free upgrade to Mavericks?
6.  If I want to do the "Data Doubler" option in the future and add a normal Solid State drive into my computer, will it have trouble interacting with the 1 tb hybrid solid state drive?
I would love to get some recommendations about the smartest option to upgrade my hard drive with something that will be fast (I edit lots of photos) and large (1 tb) that isn't going to cost too much.  I don't know much about the different brands or options (and there are so many listed in tons of online reviews), that I got really overwhelmed and confused by the info out there.
I would really appreciate any help and advice.  I've never switched out a hard drive before.
PLEASE HELP !!!  Thanks!
Here is the "About this Mac" Info:
Macbook Pro 15-in Mid 2012
Model Identifier: MacBookPro9,1
Processor: 2.3 GHz Intel Core i7
Memory: 4 GB 1600 MHz DDR3
Software: OS x 10.8.5
Storage (Hard drive): APPLE HDD ST500LM012 Media, Rotational, SATA, GPT (GUID Partition Table)

Answer 1

1.  Is a hybrid solid state drive going to need some kind of special formatting after I put it into the macbook so that I can put the operating system on it?
The boot drive, regardless of what it is, needs to be formatted as Mac OS Extended (Journaled).  This is standard with OS X.
2.  Is a "normal" platter hard drive more reliable than a hybrid solid state drive?
There are arguments pro and con.  Bottom line, SSD's and hybrid drives are still quite expensive per GB than standard hard drives.  If you have the bucks and are a speed demon, go ahead.   I have better use for my money.   Standard hard drives are mechanical and may wear out over time.  But even though SSDs are not mechancial, they can still go bad and ultimately they even have a limit to their write capacity.  The jury is still out on this debate.
3.  Is there any additional driver or special software that I have to install for a hybrid solid state drive?
No
4.  Currently there is no personal data stored on the computer.  Can I just put the new hard drive in, and then insert the snow leopard install cd?
You can physically put the hard drive in but probably not install Snow Leopard on this MBP.
The mid-2012 MacBookPro9,1 models came with Lion 10.7.3 (11D2097) preinstalled.   It is very unlikely you would be able to install Snow Leopard on it.  Historically you cannot install a version of OS X that is earlier than the version that came with your Mac (even if you replace the hard drive).
5.  If I install snow leopard, can I just go to the App store and get the free upgrade to Mavericks?
Not via Snow Leopard on this MBP.  See my response to #4.
6.  If I want to do the "Data Doubler" option in the future and add a normal Solid State drive into my computer, will it have trouble interacting with the 1 tb hybrid solid state drive?
No.  They are completely independent of each other; they are just independent storage units (drives) and their RAM does not interact.