http://pcpartpicker.com/p/zm9kkL
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i7-5820K 3.3GHz 6-Core Processor ($369.99 @ SuperBiiz)
CPU Cooler: Corsair H110i GT 113.0 CFM Liquid CPU Cooler ($109.99 @ Newegg)
Motherboard: ASRock X99 Extreme4 ATX LGA2011-3 Motherboard ($174.98 @ Newegg)
Memory: Corsair Vengeance LPX 32GB (4 x 8GB) DDR4-2400 Memory ($119.99 @ Newegg)
Storage: Samsung 850 EVO-Series 500GB 2.5" Solid State Drive ($149.99 @ Newegg)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($71.99 @ Newegg)
Video Card: PNY Quadro K4200 4GB Video Card ($772.99 @ SuperBiiz)
Case: NZXT S340 (Black) ATX Mid Tower Case ($59.95 @ Directron)
Power Supply: Thermaltake 750W 80+ Gold Certified Semi-Modular ATX Power Supply ($54.99 @ Newegg)
Operating System: Microsoft Windows 10 Pro OEM (64-bit) ($124.75 @ OutletPC)
Total: $1991.61
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-04-14 07:08 EDT-0400
If you wanted to save some more money there, you could swap the 32GB of RAM for a 16GB kit. Also, as you had in your first build, you could swap the 2TB HDD for a 1TB HDD. I do not recommend m.2 SSDs, rather stick with SATA SSDs. It is still an SSD, just a tad bit slower.
Why I chose what I chose:
CPU: The obvious reason I chose this CPU is for the 2 extra cores compared to the Skylake processor. It is a hexacore processor clocked at 3.3GHz on each core. It can also be overclocked.
CPU cooler: Whats the point of having an overclockable CPU without a proper cooler. This AIO liquid cooler will keep your temps down, and your performance up.
Motherboard: I needed something that could support everything, and I got to this.
Memory: For your specific tasks, I gave you 32GB of DDR4-2400 RAM. This is because modelling can use a lot of memory. 32GB is a way to make sure you wont run out easily. Memory also adds to multitasking capabilities, and with 32GB RAM you can multitask to the max.
Storage: I chose the Samsung 850 Pro SSD over the M.2 SSD you had put in your own list. I just recommend it, as it is cheaper and is just an all round good SSD.
Storage: I also chose a 2TB HDD for additional storage. This should last you long into the future. You can store all your projects here, and the drive has reasonably quick read/write speeds.
Video Card: I managed to find a PNY Quadro Video Card for your needs. These cards will give you better performance than the GTX cards for modelling and simulation.
Case: The case isn't that much of a stunner, but it does have enough space for everything to fit in (and it has a side panel to show off all the expensive s*** you have bought!)
Power Supply: This power supply is an amazing 750 watt 80+ gold rated power supply. If you wanted to you could add in another PNY Quadro at a later stage and this power supply would easily be able to handle it.
Operating System: I would have preferred giving you Windows 7 Ultimate, but if you want to use Windows 10 I cannot stop you there. So I just added Windows 10 for your pleasure.
This is a very expensive build. I am recommending (from my perspective) the best possible build for your needs.
If you are wondering why I would recommend Windows 7 Ultimate over Windows 10, is because Windows 10 is fairly new still and has quite a bit of bugs in it. Windows 8 and 8.1 is absolutely horrible. Windows 7 is possibly the best Windows Microsoft could ever have released. It has the most bug fixes, and is optimized for almost any application (not to mention almost all applications are optimized to run on Windows 7).