So I pretty much copied Raiju's build in this thread: https://hardforum.com/threads/custom-db4-build.1931503/ but I'm nowhere near as confident hacking components so it's a pretty off-the-shelf build.
Specs are as follows:
MB: Asus ROG Strix B350-I Gaming
CPU: AMD Ryzen 3 1300X
RAM: 1 x 16GB GSkillz RipJaws V 3200Mhz
GPU: Zotac GTX1050Ti Mini 4GB
SSD: Samsung 960 EVO 250GB
This is a HTPC box, hence the low CPU and disk space. I've still got one DIMM slot and one M.2 slot to upgrade later as needed, and hopefully AMD will be good on it's promise to support the AM4 socket till at least 2020 so I'll have a couple of generations of processors to upgrade to as well if required.
As it is I'm quite happy, the click-the-button overclock in AI Suite got the CPU to 4Ghz at 1.4V and at idle it sits between 38 and 43 degrees (ambient of around 26 degrees).

One thing I've done different to Raiju was that I've added an internal air temp sensor using the T_Sensor header on the Asus board. It's a two-pin thermistor that I got off Ebay and it's simple dangling from the 24Pin power cable into the cavity between the motherboard and the front panel. It's not a particularly elegant solution but when I complete the build (see below) I'll try to sort out a more permanent fixing point. As you can see from the above, the temp is a good few degrees above ambient, but so far, it hasn't gotten above 40 degrees. I'm interested to see what happens when I finish the build and how much that changes.

So what's left? Well as you might be able to see from the above photo, I still actually have a fan in a fanless case! I purchased the HDPlex Passive GPU Cooler Kit but ran into a small but significant problem:
it doesn't fit the Zotac GTX1050ti Mini!

As you can see, the capacitors are too close to the GPU die so when lined up with the pre-drilled holes, the block sits on top of them. The solution - I've got to tap some new screw holes. The advantage to doing that is that the block will also have pretty good coverage of the GDDR chips. The problem is figuring out exactly the gauge for the screws - I keep seeing differing views between M2 and M2.5. If anyone knows, please let me know!
So at present there is some really good airflow inside the case with that GPU fan circulating the air. What was surprising is that even whilst gaming I couldn't hear the fan at all. I haven't installed Furmark yet to give it a proper flogging, but for what my typical use case will be, I was pleasantly surprised and happy that if it gets too warm in there with the passive cooler on, I can always put the fan back on. Defeats the point of a fanless case I know, but nice to know the option is there.
Specs are as follows:
MB: Asus ROG Strix B350-I Gaming
CPU: AMD Ryzen 3 1300X
RAM: 1 x 16GB GSkillz RipJaws V 3200Mhz
GPU: Zotac GTX1050Ti Mini 4GB
SSD: Samsung 960 EVO 250GB
This is a HTPC box, hence the low CPU and disk space. I've still got one DIMM slot and one M.2 slot to upgrade later as needed, and hopefully AMD will be good on it's promise to support the AM4 socket till at least 2020 so I'll have a couple of generations of processors to upgrade to as well if required.
As it is I'm quite happy, the click-the-button overclock in AI Suite got the CPU to 4Ghz at 1.4V and at idle it sits between 38 and 43 degrees (ambient of around 26 degrees).

One thing I've done different to Raiju was that I've added an internal air temp sensor using the T_Sensor header on the Asus board. It's a two-pin thermistor that I got off Ebay and it's simple dangling from the 24Pin power cable into the cavity between the motherboard and the front panel. It's not a particularly elegant solution but when I complete the build (see below) I'll try to sort out a more permanent fixing point. As you can see from the above, the temp is a good few degrees above ambient, but so far, it hasn't gotten above 40 degrees. I'm interested to see what happens when I finish the build and how much that changes.

So what's left? Well as you might be able to see from the above photo, I still actually have a fan in a fanless case! I purchased the HDPlex Passive GPU Cooler Kit but ran into a small but significant problem:
it doesn't fit the Zotac GTX1050ti Mini!

As you can see, the capacitors are too close to the GPU die so when lined up with the pre-drilled holes, the block sits on top of them. The solution - I've got to tap some new screw holes. The advantage to doing that is that the block will also have pretty good coverage of the GDDR chips. The problem is figuring out exactly the gauge for the screws - I keep seeing differing views between M2 and M2.5. If anyone knows, please let me know!
So at present there is some really good airflow inside the case with that GPU fan circulating the air. What was surprising is that even whilst gaming I couldn't hear the fan at all. I haven't installed Furmark yet to give it a proper flogging, but for what my typical use case will be, I was pleasantly surprised and happy that if it gets too warm in there with the passive cooler on, I can always put the fan back on. Defeats the point of a fanless case I know, but nice to know the option is there.