@fjbruening I second/third/fourth what others have said regarding CPU and motherboard choice. Honestly the new i3 6100 is pretty slick. New hardware even on the "low" end spectrum is just so wicked fast. It is an awesome time to be building PCs. I know it is so tempting to want to put the high end stuff in a build, but if you are truly just looking for a fantastic 1080p experience, you can do the i3 6100 with a 1060 and a VNAND SSD and have a killer system. Even the 1050 is pretty sweet for most things at 1080p.
Money isn't the only tradeoff, the other is heat, which is my next question to answer:
Just a poll - does anyone have any issue with the case heating up substantially when under load?
I actually have been using the front bezel as a heatsink for the HDPLEX for my custom builds. I use thermal padding against the HDPLEX aluminum backplate. You can go crazy and put some thermal paste in between the chassis and the front bezel too, but that is a bit extreme.
As far as the GPU cooling, I'm going to dump my thoughts on the table and you can see if anything is useful to you.
There are better ways to keep parts in a 4L chassis cool than the S4 Design. The S3 is a far better thermal layout. One day I will bring it back (with some new breakthroughs) to serve the needs of customers who want to pack as much high performance stuff in a small box.
I don't think the S4 MINI's thermal design is flawed, however, as it was meticulously designed. It started off being capable of exhausting a tremendous amount more heat, but the goals of the chassis (combined with the extremely small market) had me trade those benefits for customer CHOICE. The S4 MINI starts off as elegant as I can make it. With two mods you can bring back the cooling efficiency, but they will dramatically (or minimally) impact the design depending on how much time and money and artistry you put into them.
The ideal TDP for the unmodified S4 MINI <50w for the CPU, and <100w for the GPU. At those TDPs the system will be able to maintain a cool environment. You can build a pretty slick system for this TDP range now too. This might seem low, but I would respectfully ask you to consider the cooling performance of other small form factor cases available for retail. I'm hesitant to release comparisons myself of the Raven RVZ0 or the Node 202 but just compare the venting of the MINI to them.
Now 90%+ of my customers exceed this by a huge range. The 285ITX, ASUS 970, and Gigabyte 1070 account for 80% of my custom builds, and NO system I have ever been asked to build was under 185W. They choose the high temperatures as their poison for having so much burst power at their fingertips. That being said, removing the bezel allows your GPU to exhaust as much heat as its heatsink design allows while in the vertical format. Adding ventilation to the top will allow for the adequate cooling of 85W CPUs with the Noctua NH-L9i.
It just depends on how far you want to go to dress it up.
I am waiting on Xen right now to invest my S4 MINI, but I will have some examples of what you can do as a modder to enhance your MINI. I would ideally like to have a gofundme or something so I can get a decent sized CNC in my shop so I can do the mods and personalized engraving for your guys myself. But anything I do offer on my website I will provide CAD for so you can get it done locally!
Peace