I want to buy iMac. Need tips and answers

Question

I'm considering high to purchase the iMAC 27-inch 3.1 Ghz i5 and if my question are well answered, with god grace, I will confirm my order on the launch of LION OS.
The iMac will serve the purpose as mentioned below
1. I'll be working on with Pro Logic Music Full Edition (for the purpose of composing and arrangement musics)
2. Aperture 3
3. Final Cut Express
So basically I'll be working on publications, some video and music composing and editing. So thats my main purpose.
However, I'm having consideration to upgrade
1. Is it worth it to upgrade form i5 to i7 processor? Obviously there will be increase in speed. But my question is, doest it really shows a significant speed from upgrading from i5 to i7? Can I see the processiong speed increase alotz? and if it increase, is it just little or huge difference?
2. The pre installed is 4GB, by increasing it to 8GB, will I see any significant differences, especially when working out on logic express and final cut, as i believe it needs alot of memory usage. However, does the 3 applicaiton, supports upto 8GB or what? Does it really contribute to significant of increased performance?
3. Upon purchasing my iMac, I woud like to attach another 2 units of Samsung 27 inch FULL HD supports upto 1920 x 1080 screen resolution. So basically, there will be 2 separate monitors + 1 iMac. So is it necessary for me to upgrade to the 2GB Graphics Card?? Or just leave it as 1GB. By splitting the monitors, do I really need higher resource of graphic card? i'm NOT going to play GAME. I've heard some issues, whereby when they split the monitors, there appear to be some black coverage area, and the screen size is not maximise.
4. I currenlty own a External Sound Card Powered by the FireWire 400mbps, the iMac mentioned it supports up to 800mbps, so can my external sound card support the iMac. ( This is for recording and output purpose) as I won't be using the iMac speakers, instead attaching a huge Powered Speakers to my External sound card.
5. Finally, I'm interested in purchasing the Thunderbolt Peragus Drive which can support up to 4 to 6 terabytes. So the problem and issue now is, iMac provides
1 Fire Wire - (which I will be using for External Sound Card)
Thunderbolt - 2 units, which I will be using it for 2 monitors
Peragus Thunderbolt Drive - I HAVE LACK OF ONE THUNDERBOLT CONNECTION. SO HOW?
can I use the 1 unit of thunderbolt to output into 2 EXTRA MONITORS?? My monitor supports HDMI, and DVI signals. And If yes, Will there be a PIXEL DISTORTION or BREAK?? I mean I really want a clear view of the monitor, without any loss of quality. So please suggest me. I'm extremely new to MAC, and I need very good professional advice.
I would be thankful, if you guyz could answer me clearly, according to the question.

Answer 1

Kalimullah Khan wrote:
I'm a bit confuse.
1. You mentioned to install another 8GB. Are you trying to say the total memory will be 12GB??
How's the situation. Is it like this
1st Slot - 2GB
2nd Slot - 2GB
3rd Slot - 4GB
4th Slot - 4GB
Yes if the way the slots are numbered result in matched pairs of memory, i.e. nothing to worry about if the Apple-supplied memory is not touched as they’ll be a matched pair; just add the two 4 GB sticks in the two empty slots. 
If you don’t install the memory in matched pairs, it will work but you won’t have dual path access to the memory so the memory will be slower.
When you sum up, you get total of 12GB, which I don't think so can be configured in apple store. The options are 4GB in each slot, when you plan to upgrade from 4GB to 8GB or 16GB only.
Yes, the total would be 12 GB and you buy the additional 2x4GB memory sticks from either Apple at the time you purchase the computer or from a third-party vendor - but you must be careful to get the correct type of memory.  Sites like OWC can be very helpful guiding you.  If you buy from Apple, you cannot add to the device via the configuration options as you pointed out.  But once you initiate the online purchase, you’ll be able to Continue Shopping for other items such as memory to Add to Cart before you Checkout.  It’s easy to install memory yourself.  Just be careful to buy the memory exactly designed for your machine!  Any tiny variance and the memory won’t work; it’s not too difficult but read the specifications carefully.
2. You mentioned that I don't need 2GB memory card, however, my question is, by splitting the monitors into another 2 additional monitors, will the graphic display will be compromised or not? To be more clear, will I have an accurate display or a bit less quality display?
I am sure that graphics card with 1 GB will support the three displays if you are not using the computer for gaming.  If you are gaming, then you might want the 2 GB card.  You can prudently call Apple to discuss if you like.