Quad as in the CPU.
Matrix RAID is something available on Intels ICH9R (and some previous versions). It allows you to run a RAID 0 array, and a RAID 1 or RAID 5 array on the same group of HDDs. Plus the "slice" you cut out for your RAID 0 array can be comprised of the fastest part of the HDDs to give you even faster load times/speeds for your OS, games, and programs. Very cool stuff...check out the Matrix RAID sticky in the storage forum.
If you're planning on doing SLI in a year I highly recommend you just sell your current GPU at that time, and buy a newer one. Whatever is out by then will probably tromp 2 GTX's in SLI anyway. You have a 36" LCD HDTV...must be 720p or 768p, right? I don't know if 1080p's come that small. At those resolutions you are already overkill w/ your GTX. I've got a 720p projector (95" on the screen), and my 320MB 8800GTS has no problems w/ all the current games on high settings.
As far as 8GB RAM...have you checked to see if those programs are using more than your current 4GB? (check task manager...bottom right corner...if left number is more than 4048M when you're program(s) are running then you may need more RAM) If they are then by all means go for 8GB, but I haven't heard of any case so far where anything more than 4GB was actually being used at a given time. With those programs you're running, though, you may be a candidate.
I'd look to X38 or X48 if you're going to be waiting. It supports PCI-e 2.0, so if you do get a new GPU in a year it might actually be able to take advantage of the extra bandwidth. I'm not sure if SLI will be officially supported on the X38/48, but you can be sure some hacked drivers will be out there for it. X38 should be out by next month...X48 shouldn't be too far behind. nVidia may release a new MoBo chipset in the coming month(s) as well, but I haven't heard anything concrete yet. Lots of choices coming! If you're going to wait anyway, see what's out at the end of the year, and wait to buy it right after the new year. If you don't want to wait too long wait till the end of the month and get an X38 when they first come out. If you can't wait at all get a P35...or 680i if you must have SLI.