Need help with 4 display computer/graphics card setup

[godsdabomb]

Hello, our church is hoping to make some upgrades to our current video setup. I need help to figure out the best way of going about it (in relation to video cards and more). Any helpful thoughts or recommendations are appreciated.


Here's what we would like to do ideally:


We would like to run one display to a control monitor currently connected to our integrated GeForce 9100 via DVI. Then, I would like to run a second extended display via VGA that runs to our VGA multiplier, back to a viewer monitor and out to our two projectors and two screens (this also currently connected via the integrated 9100, but we have a lot of lag, so a dedicated card may be needed to replace this). Thirdly, I would like to send a third display to a new 55" flatscreen we plan to put on the back wall that is visible from the stage. And finally, I would like to send yet another feed to a fourth set of HD monitors/tvs that would be cloned out in our Lobby/foyer where we could run announcements. We would also like to feed video from our Canon XL1 into this computer via firewire so that it can be recorded to the harddrive as well as displayed live on the screens out in our lobby and possibly even in our main auditorium (so minimal to no lag is crucial). Sooner or later, Of course, I would like all of these things to be run from one computer, as the first two displays are currently run through our presentation software that is called Songshow Plus 7. We would also like the ability to run our video through this computer to make live video a possibility and then distribute it to the main projectors and lobby hdtv's, but that isn't necessary right now.

Are we hoping for too much? Which dedicated graphics card(s) are needed and will we need to upgrade psu to handle them? Can this all be done from one computer? How can we do this in a way that we don't have to do it all over again when we want to move to live video?

We have a budget of about $2000 after the tvs.

Here is what we have for a computer:
HP Pavilion a4316f-b

Spec Data
Type Mainstream
Processor Family AMD Athlon II
Processor Speed 2.6 GHz
Processor Name AMD Athlon II 620 Quad-Core
RAM 6 GB +2 GB upgrade
Storage Capacity (as Tested) 1000 GB
RAID No
Graphics Card nVidia GeForce 9100 (256mb and currently lags with video usage through our presentation software) (the expansion slots are 1 - PCI-e x16, 2 PCI-e (x4?), and 1 PCI (1))
Primary Optical Drive DVD+/-RW (Plus Minus)
Monitor Type LCD Widescreen
Screen Size 20 inches
Operating System Microsoft Windows 7 Home Premium
Native Resolution 1600 x 900
3-D BENCHMARK TESTS 3DMark06 - 1280 x 1024 - Default 2614
MULTIMEDIA TESTS - CineBench R10 (xCPU) 9884
PSU - 300 W Alinc (I imagine this could be a problem and may need to be replaced if two dedicated gpu's are needed.)