So I just learned about needing more drives....

Question

I thought I was well off. Turns out after time on this forum, I am a newbie again..... ah, what a feeling.
I have one hard drive. It's a 1TB and called HITACHI HDT721010SLA360 ... whatever the heck that means.  Anyway... what kind of hard drives can or should I buy? Should I get the same ones? I hear you should have the same ones all across.  If so, what sizes? I am editing a movie I made for fun and it is about 30 min long and editing is slow. It is fast to edit when i have only like 5 min of timeline footage. But now the project is up to like 20 min and everything runs slow....
So any suggestions guys? What is compatible with my PC and should be upgraded? I know I need more hard drives. I have also just purchased a second monitor so I can have one to view my video and one to edit the timeline. I hope this was a wise choice... it only seems logical and I have used it just now and it seems easier to edit without having to resize workspaces constantly.
And if I need a new computer all together, let me know... I would rather not, however. If I must, I would consider some company who specializes in video editing builds, which I've read on this forum there is one called ADK who makes these systems.
YOU ALL ROCK! This is a great community and hobby to be apart of... although for some it's their job(and I wish to mine in the future as well)
Thanks to NEWEGG for keeeping so much order history, I found out all the specs of my computer in no time! Here it the list directly from when I bought it in 2009(I have upgraded to WIN 7 now by the way) :
Brand
iBUYPOWER
Model
Gamer Supreme 928i
Type
Gaming
Processor
Intel Core i7 920(2.66GHz)
Processor Main Features
64 bit Quad-Core Processor
Memory
6GB DDR3 1333
Hard Drive
1TB SATAII
Optical Drive 1
22X DL DVD+/-RW Drive
Graphics
NVIDIA GeForce GTX 285 1GB Video Card
Audio
Realtek chipset
Ethernet
10/100/1000Mbps
Power Supply
800W
Keyboard
iBUYPOWER USB Deluxe Keyboard
Mouse
iBUYPOWER USB Mouse
Operating System
Windows Vista Home Premium 64-bit
Free MS Windows 7 Upgrade
Special Features
PSI SILVER ARMORX Gaming Case + Blue color lighting
Motherboard
Chipset
Intel X58
CPU
CPU Type
Intel Core i7
Installed Qty
1
CPU Speed
920(2.66GHz)
L2 Cache Per CPU
4 x 256KB
L3 Cache Per CPU
8MB
CPU Socket Type
LGA 1366
CPU Main Features
64 bit Quad-Core Processor
Graphics
GPU/VPU Type
NVIDIA GeForce GTX 285
Graphics Interface
PCI Express 2.0 x16
Memory
Memory Capacity
6GB DDR3
Memory Speed
DDR3 1333
Memory Spec
2GB x 3
Memory Slot (Total)
6
Memory Slot (Available)
3
Maximum Memory Supported
24GB
Hard Drive
HDD Capacity
1TB
HDD Interface
SATA II
Optical Drive
Optical Drive Type
DVD±RW
Optical Drive Spec
22X DL DVD+/-RW Drive
Audio
Audio Chipset
Integrated
Communications
LAN Chipset
Integrated
LAN Speed
10/100/1000Mbps
Front Panel Ports
Front USB
2
Front eSATA
1 x e-SATA (based on motherboard availability)
Front Audio Ports
2
Back Panel Ports
PS/2
2
Video Ports
2 DVI
TV Out
1
Rear USB
6
Rear IEEE 1394
1
eSATA
1
RJ45
1 port
Rear Audio Ports
6 ports
S/P DIF
1 x Optical S/PDIF output
1 x Coaxial S/PDIF output
Expansion
PCI Slots (Available/Total)
3 x PCI-Express x16
1 x PCI-Express x1
2 x PCI
Physical Spec
Dimensions
17.4" x 17" x 7.9"
Weight
36 lbs

Answer 1

So I got my 24 gig of ram and 2 extra drives. Everything is installed and registered in Windows 7 64bit.
An important note to add to anyone considering an upgrade, seeing that I had some troubles with all of it:
First, Windows 7 Professional or Ultimate(64 bit editions, of course) is the only ones capable of running any more than 16gb of ram. I had to pay an extra $90 to upgrade my Win 7. That is stupid, Microsoft!
Second, everything was recognizd except for one hard drive. I had many theories such as, my mobo only supports 3 sata devices at once, my psu can't output enough power, or bios has some settings I need to enable. Turns out, after HOURS of taking this cable from this place and trying it in this place and all this garb, I found that one of the manufacturers SATA cables were bad! hardly noticable, but when i peeled back some of the covering on the wires, I see the wires are not fitly joint.
Third, a big computer case would be HIGHLY reccomended. In my case(no pun intended), the drives barely made the fit! Had heck of a time doing that. Especially with all the wires crammed everywhere.
So anyhow, I'm here transferring my media(video/audio files of my projects and other recordings I often re-use) to my second drive as Harm reccomended in his general hard disk guide. The only thing I am confused about, harm, is that you say to do Exports to a third drive. Are you referring to when I literally export my project? This would only make exporting faster and not the actual workflow, correct?
Let me know if you can. And as you know, I will probably have a few more other questions after this about the setup while going through Premiere. For now I'm just transferring media(125 gigs).
Thanks!
MrD