This is where I currently am, if I were buying today:
Fractal Design Arc Midi R2 Mid-tower case (currently on sale for $75.00)
ASUS Z97-PRO(Wi-Fi ac)/USB 3.1 LGA 1150 wireless motherboard ($215 - currently out of stock)
- or -
ASUS Z97-A/USB 3.1 LGA 1150 motherboard ($149)
Intel Core i7-4790K Haswell Quad-Core 4.0GHz LGA 1150 CPU ($340)
Noctua NH-U9S Premium CPU Cooler ($58)
G.SKILL Ripjaws X Series 16GB (2 x 8GB) 240-Pin DDR3 1866 RAM ($109)
SAMSUNG 850 Evo Series M.2 250GB SATA III SSD ($120)
be quiet! BN635 Straight Power 600W PSU ($143)
EVGA GTX 960 Superclocked 2GB GDDR5 PCI Express 3.0 Graphics Card (currently on sale for $200)
With current pricing that puts the build in the $1,194 to $1,260 range, so it remains more or less within my goal of $1,250 or less per build. Of course, an eventual new 4K monitor and keyboard will blow that out of the water by some $500~.
The more I researched RAM for this build, it seems no more than 16GB of DDR3 1866 is an ideal match for the i7-4790K CPU. There's a lot to consider with frequency vs. price vs. voltage, but 1866 seems to be the sweet spot. Higher frequencies need more voltage and only make a difference in benchmarks. I probably don't need more than 8GB total, but the price for 16GB is doable.
I'm currently leaning toward the ASUS Z97-A mobo for $149, although it does not include wireless. I suppose I could add that myself later.
The case is currently on sale and I'll probably order it after poasting this. Last time I looked it was $110 + $15 shipping. Today it's $75 with free shipping. It's available in a window version for $5 less, but that's not a feature I really care for.
I don't have a firm decision on the graphics card. I'd prefer a GTX 970, but the GTX 960 is no slouch and it's well over $100 cheaper. Current GTX 970 cards are starting at $330, making the GTX 960 a bargain at $200.
As for the storage, the M.2 drive is not PCIe. But the price is right and the performance should not disappoint. I also like the fact that it's a plug and play solution, as compared to PCIe, which is not entirely without its issues. I'll almost certainly go for an external storage solution, such as this
Samsung 500GB USB 3.0, currently selling for $216.
I probably won't immediately need a graphics card. Earlier today my son-in-law gave me a GTX 465 card, so that can easily hold me over for awhile if needed.
This build is going to happen, so any advice, comments, thoughts are certainly welcome.
EDIT: I just ordered the Fractal Design Arc Midi R2 case.