Help an aussie spec a system

Question

Hallo y'all.
Building a new system in the next week or so, and would like some advice on optimising the value of my build to take advantage of Adobe Premiere Elements 8. The main initial task will be editting some low quality MPEGs of 9hrs/10GB of my grandfather talking about his life and involvement in WWII. It'll mostly be very simple cutting and editting, but I would like to play around with some of the other features without having to twiddle my thumbs too much, and the system is intended to last for at least 3 years.
I'll definitely be getting or re-using:
- CoolerMaster 690 case
-  ATI HD 5770 1GB (I'm a casual gamer)
- Windows 7 Home Premium 64-bit
- KB/Mouse/23.6" LCD/Speakers/Printer and other peripherals all fine
and these parts may be useful salvage from the existing PC (but am willing to replace if I get a value for money increase in performance):
- Samsung 400GB 400LJ
- Samsung 400GB 403LJ
- Samsung 640GB 642JJ
- 2GB Transcend DDR2-800 5-5-5-18
- Pioneer DVR-118L (PATA, so mainboard will have to have PATA if you want to re-use)
Need all other parts. Don't need Blu-Ray. Have a budget of $AUD1,000 for everything (not including the "definitely be getting or re-using" list) and will be shopping at MSY. Price list here - a bit of an annoying format unfortunately, but they're the best priced around and I'm not far from them. You can, if you like, also select things from NetPlus, PLE and Austin, but you'll note MSY are generally a better price and I have to get the majority of the thing from one place to get the OEM Windows license.
I've been servicing computer for a living for the last 8 years, so no need to worry about help physically building the thing.
I understand the program properly supports quad core (in that it'll actually use all 4 cores and max out the CPU if the task requires it), but I'm having trouble finding official confirmation of that and benchmarks to show the actual performance difference. Does anyone have any convenient benchmarks that show performance differences between things like platforms, DDR2/DDR3 at different bandwidths and number of cores? It'd make the process a whole pile easier as I've mostly been going on generalisations based on other programs being benchmarked like Premiere CS4.
From what I've seen of other benchmarks, the LGA1366 platform doesn't give a value for money performance advantage unless you're into Crossfire/SLI and the AMD offerings like the Phenom II X4 945, 955 & 965 don't compete that well with the Core i7 860. In the above linked CS4 benchmarks, the i7-870 seems to be almost twice as fast as the i5-750, which doesn't make a lot of sense to considering they have the same cache and only 266MHz difference. Anyone know why that is? Presumably some kind of i5/i7 architectural difference, but it does seem bloody wierd. It'd also be nice to know what "editting video" as a task means, but hey.
Higher bandwidth RAM doesn't seem to help, as the latency does go up as well. But since there's only a marginal price difference between DDR3-1333 and DDR3-1600 ($20 for 8GB), might as well get the DDR3-1600.
What I think would likely go best:
- Gigabyte P55-UD3R $149
- 2 x 4G DDR3 1600 Patriot-Signature/G.Skill-NQ $125ea $250
- Intel Core i7-860 $340
- Antec EarthWatts 650W $121
- Seagate 1.5TB $141
Total $1001
Obviously I'd be re-using the HDDs and Optical on that build. The PSU is a little overkill since the system likely won't draw more than 200W for most operation and 250W under heavy CPU + GPU load, but again I save only a little by getting a weaker one (of equal or better quality). I went with the 860 because of the aforementioned wierd Tom's Hardware results, but if someone's certain that's, well, wrong, I can drop to the i5 750 and get a second HDD. I'm uncertain the model of the Seagate though, so will call them tomorrow to check that and to make sure it's a good 'un.
Would you suggest something completely different?
Bonus question:
What is the best HDD configuration re: fastest drive to each task? e.g. Scratch=Fastest, Media=Second, OS/Program=Slowest.
I apologise for the extended and likely unnecessarally long post.

Answer 1

A historical perspective.
As you rightly mentioned, at the time I wrote the Lynnfield versus Bloomfield article those price differences were right, but in this very volatile market with daily price changes it may no longer be accurate. The CPU prices of 17-920 and 17-860 are about equal, as are their performances. Of course the P55 versus X58 price difference still holds at around the same comparative advantage for the P55. You also mention the PCI-e lane difference, which IMO is the most important difference.
And now...
the i7-860 is attractive if you are certain you will not need additional PCI-e lanes and/or will want to upgrade to the Gulftown. Otherwise the 17-920 is still the way to go, because you also have the advantage of 12 GB of memory instead of only 8 GB on a P55 with CS5 being 64 bit.