Arctic Silver 5 - not required with the Freezer 7 Pro. It comes with AC MX-2 thermal compound pre-applied for easy installation. AC Freezer 7 Pro review If you plan to have the HSF off after install then will you need extra thermal compound. Try AC MX-2 it's non-conductive and easy to work with.
In part it depends on how you use your system.
The biggest difference would be the boot time with Raptor being faster. Example:
If you're like me and only boot Vista once a week or less its not such a big deal.
You can expect the peformance to be along these lines:
Those differences probably aren't enough to notice unless you break out a stopwatch.
What you would more likely notice (if you had both types of drives side-by-side) is how much quieter the non-raptor drives are.
By the time you might want to get a second card...its stupid because the new card is better than the SLI. Unless you plan on doing it in say 6 months then I say go ahead...anything longer and its silly
I'd skip the Raptors and WD all together. Seagate 7200.11's are the better buy IMO and come with a 5 year warranty. WD is having a hard time competing with the big boys of late and looks to be a ripe target for acquisition.
Unless you have a strong reason (i.e using PC Power & Cooling) , I'd use the same vendor for PSU and Case. Thermaltake PSU is $149 after $40 rebate whereas the Antec 850 is $129. Lotta Thermaltake cases that I like .... depends on whether you like the lights and stuff or more plain models.
Watch out for PSU issues with a G92 based vid card....most PSU vendors having irksome random timing issues with them.