Some comments about the build,
Intel Core i5/7-4x90, 65 W TDP, exact model depending on price, not sure if I need the i7?
As other have posted, check if you program/apps/games will use hyperthreading, else save $100 and go with i5. Would be interesting to see the new asus fanXpert3 if you can show the if the fans are truely PWM headers.
Crucial 16 GB RAM kit (2x8)
Crucial M550 512 MB
I been a fan of crucial for a long time, tons of memory, and never had issues with them, i own a couple Crucial M4 and they been perfect. But personally i dont like the M550 temps, specially for us that slow down our fans so much. I would suggest to take a look into Samsung 840 Evo or Sandisk Extreme II.
nVidia GTX 770, 220 W TDP -- how about the Asus GeForce GTX 770 DirectCU II? The 220 W TDP worries me a bit, as I've always tried to stay below 150 W before, but the GTX 760 doesn't seem to be powerful enough for 1440p, never mind future-proof. How is the power management on these, does the fan run while gaming only?
I agree with CA_Steve, i think we are getting closer to the new series, i would invest the least you can atm like GTX750ti or none ti, and wait for the new gen to invest more heavy. Personally i didnt like the GTX770 that much, although a fine card, its a GTX680 with faster vram, still very capable GPU, but i would prefer either to invest on GTX780 or go down to GTX750 and wait for the next gen.
Antec Solo II -- not exactly a current or cheap model, what else is there? (USB3 on the front panel is a must.)
Sea Sonic Platinum Fanless 520W
This is a very nice combo for the SOLO II, specially with the open top mounted PSU, but as a warning if your PSU is noisy by any chance, some have experience coil whining or electrical noise with Seasonic, then it would hear much more on this setup because of its open top. That said, i own a X400, X660 and two SS860XP2, the only one that has a little coil is the X400 if you place your ear right next to the PSU, but you cant hear at 1mt even on a very quiet room watching movies. Personally im extremely happy with sesasonic and will still be my first choice on PSU until they disappoint me, but this is more a warning in case you do in fact are unlucky.
Noctua fans -- which ones, how many, at what speed? I've got a few new ones around somewhere
Personally i love noctua PWM fans but not out of their tone, but out of the range of control they have, simply the best in the market imo. Now on the tone, i think noctua fans are good as long as you dont spin them very high, where other fans have better tone imo.
First decide on the case, Antec Solo II is a good option, i own one that i use on HTPC, but for high end card i would probably go Fractal Design Define R4 as its more closed with the PSU not up, and the fans are 140s and you can place 7 if you open the modu vents, not that its needed, but its nice to have options.
Now back to the fans chioce.
1) Antec Solo II
Read SPCR Fan Roundup #6: Scythe, Noiseblocker, Antec, Nexus, Thermalright
, in this roundup they test a lot of what i would say the best ones in the market, like Noiseblocker M12-S1 or Scythe Gentle Typhoon, they also test Nexus Basic 120 that its a pretty good option in price, and you are lucky as they also test the Antec True Quiet 120, the fan that its included with your SOLO II. Depending on your budget, i would go Noiseblocker M12-S1/2 depending on your cooling needs, Nexus Basic 120 or Scythe Glidestream are good candidates if you dont want to spend that much.
2) Fractal Design Define R4,
Here gets a little simpler, as there are not that many options on the market for 140s. That said, i would recommend you read both SPCR roundups of 140s, is fairly recent and has very good info on them, First 140 mm Fan Roundup: Noctua, Phanteks, XigmatekSecond 140 mm Fan Roundup: Antec, bequiet!, Corsair, Scythe
If i was to go with Asus FanXpert motherboard, i would chose Antec True Quiet 140s, imo among the best tonally and has a very good range of operation, drops to 200rpms on FanXpert, and 800rpms is still a very good quiet top speeds, tonally imo is the best 140 i have tested.
Now if you are set on Noctua fans, like me, then i would go full PWM and with a motherboard has more than 1 true PWM fan header confirmed (asus suppose to have changed their only 1 true PWM fan header, but as of now i dont have any experience, so could be a marketing gimik, as they have done in the past). So i would go with a MSI, most of their motherboards have CPU_FAN1 and CPU_FAN2, that are true PWM fan headers, and that you can setup and dynamically control from the bios. Look into MSI H97 GAMING 3 LGA 1150 Intel H97 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard
. You can check my build on my signature where i mostly used NF-A14 PWM for the R4.