Some more thoughts for you:
I am not much in favor of planning on cf/sli up front unless a good single graphics card will not do the job.
If you will be gaming on triple monitors, or are a professional gamer with an unlimited budget, then sli/cf is ok.
Here is my canned rant on that:
-----------------------------Start of rant----------------------------------------------------
Dual graphics cards vs. a good single card.
a) How good do you really need to be?
A single GTX650/ti or 7770 can give you good performance at 1920 x 1200 in most games.
A single GTX660 or 7850 will give you excellent performance at 1920 x 1200 in most games.
Even 2560 x 1600 will be good with lowered detail.
A single gtx690 is about as good as it gets.
Only if you are looking at triple monitor gaming, then sli/cf will be needed.
Even that is now changing with triple monitor support on top end cards.
b) The costs for a single card are lower.
You require a less expensive motherboard; no need for sli/cf or multiple pci-e slots.
Even a ITX motherboard will do.
Your psu costs are less.
A GTX660 needs a 430w psu, even a GTX680 only needs a 550w psu.
When you add another card to the mix, plan on adding 150-200w to your psu requirements.
Even the strongest GTX690 only needs 620w.
Case cooling becomes more of an issue with dual cards.
That means a more expensive case with more and stronger fans.
You will also look at more noise.
c) Dual cards do not always render their half of the display in sync, causing microstuttering. It is an annoying effect.
The benefit of higher benchmark fps can be offset, particularly with lower tier cards.
Read this:
http://www.tomshardware.com/reviews/radeon-geforce-stutter-crossfire,2995.html
d) dual card support is dependent on the driver. Not all games can benefit from dual cards.
e) cf/sli up front reduces your option to get another card for an upgrade. Not that I suggest you plan for that.
It will often be the case that replacing your current card with a newer gen card will offer a better upgrade path.
The GTX780 and amd 8000 series are not that far off.
-------------------------------End of rant-----------------------------------------------------------
Modular allows you to remove unused leads from your psu.
If you have properly sized your psu, there will not be many.
In a normal case, there are plenty of places to tuck unused leads out of the main airflow path.
I see modular as a non issue. If you will be using a small form factor case, then OK.
If you can, stick with two sticks of ram.
Because all sticks must be controlled to the same voltage, it is easier for a motherboard to manage two sticks vs. 4.
Since ram is so cheap, and your budget is comfortable, I suggest you buy 16gb in a 2 x 8gb configuration up front.
I suggest this kit:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231558
Realize that if you want to access more than 16gb, you need windows 7 pro or ultimate.
On Tom's heirarchy chart, the GTX670 is comparable to the 7950.
But, after reading this review, comparing the 7950 to the GTX660ti, I wonder.
It seems that there is more to performance than average FPS. Read the review carefully and look at the charts of consistency of response times.
I do not know if this behaviour carries across to all amd cards.
http://techreport.com/review/23981/radeon-hd-7950-vs-geforce-gtx-660-ti-revisited
Yes, once you get past the Bios post, windows starts up in 10 seconds with a SSD.
For what it is worth, I don't boot cold very often. I use sleep to ram instead. Restarting is 2-3 seconds.
If you have sufficient ram, your games will tend to reside in ram, and a relaunch is only a second or two.
With a SSD, installing windows happens very quickly, as does the large initial maintenance updates.
Past that, everything you do will feel much quicker. Game level loads will be quicker.
All 120/128gb ssd's have the same capacity. It is just a matter of how much spare is reserved for performance, and truth in advertising.
You will actually be able to use 110gb or so.
Do not try to go smaller. A SSD will lose performance as it approaches being full.
I suggest the Samsung 840 120gb SSD which sells for $99
http://www.newegg.com/Product/Product.aspx?Item=N82E16820147188