Ok it's been ages since I've updated here, mostly because of exams but also stuff takes ages to arrive. Luckily this should be a fairly big update covering the progress I've made to make up for the silence.
Finally decided, bought and torn down the mini pc I'm planning to use. It's an Intel Skull Canyon Nuc with an Intel® Core™ i7-6770HQ processor with Intel® Iris™ Pro graphics. First some pics then I'll get into why I chose it.

I'd looked at this NUC a while ago but had discounted it based on the width of the case, at the time it still hadn't been released and it looked a little too wide for a hand-held device. However thanks to a teardown on tweaktown.com I could see that much off the width was actually the fan and heatsink and the board itself is only about 14cm by 11cm so should work fine. I decided this would be the perfect motherboard for the DSB because it has no problem running programs like Photoshop or even Blender so I wouldn't need to find alternative software and change my workflow. Plus it should be able to run games pretty well given Intel is primarily marketing it as a gaming mini pc. Apparently you can hook it up to the new external GPUs that are starting to show up and use it for VR and rendering but I'm sceptical how well that works right now.


I'm going to have to do a bit of work hacking together a new heatsink that comes directly out the back on top of the CPU instead of to the side. I'll probably leave a hole in the case just to give as much airflow as possible over the heatsink since the better the passive cooling is, the less the fan will have to be on draining the battery. Plus, I think a nicely designed copper heatsink could look pretty good.
The Nuc is supposed to run off a 19V, 120W AC-DC power adapter which bascially means the batteries I was planning to use aren't going to work. But I've got a new external battery, 40,000 mah this time and capable of powering anything from 12V to 21V. I've tested it out already and it seems to work perfectly, I was worried it wouldn't be able to supply a high enough current to power the Nuc when gaming but it seams to be fine.
The Nuc also has another advantage over the other boards I've been looking at which is that it can run displays with resolutions higher than 1920 by 1080. Given that the screen I'm planning on using has a 1440×2560 native resolution this works out well. The screen I've chosen to use is a 5.98 inch 2K LCD HDMI display made by
Topfoison, it's designed for use with VR but works well as a normal monitor as well.

One thing I'm thinking of looking into is getting some polarising film to reduce reflections for when I'm using it outside. I remember how my gameboy colour became virtually unusable in direct sunlight and while I know the screens are completely different even with indoor use I can see reflections could be an issue with this screen.

Heres the Nuc's specs for the curious:
Processor
6th generation Intel® Core™ i7-6770HQ processor with Intel® Iris™ Pro graphics (2.6 to 3.5 GHz Turbo, Quad Core, 6 MB Cache, 45W TDP)
Memory
Dual channel DDR4-2133+ SODIMMs
1.2/1.35V, 32 GB maximum
Graphics
Intel® Iris™ Pro Graphics 580
1x HDMI* 2.0 (4K 60 Hz)
1x Mini DisplayPort* 1.2 (4K 60 Hz)
1x DisplayPort* 1.2 via Type-C
Audio
Up to 7.1 multichannel digital audio via HDMI or DisplayPort signals
3.5mm front headset jack, 3.5mm rear speaker/TOSLINK combo jack
Peripheral Connectivity
Thunderbolt™ 3 (40 Gbps) or USB 3.1 Gen2 (10 Gbps) via USB Type C connector
2x front USB 3.0 (one charging)
2x rear USB 3.0, 2x internal USB 3.0 and 2x internal USB 2.0 via header
Consumer infrared port on front panel
Storage
2x M.2 22x42/80 (key M) slots for SATA3 or PCIe* X4 Gen3 NVMe or AHCI SSDs
SDXC slot with UHS-I support
Networking
Intel® I219-LM 10/100/1000 Mbps Ethernet
Intel® Dual Band Wireless-AC 8260 soldered-down, (IEEE 802.11ac 2x2, Bluetooth* 4.2, internal antennas, Intel® Wireless Display 6.0)
Power Adapter
19V, 120W AC-DC power adapter
Additional Features
OS certs: Microsoft Windows® 10, 8.1, 7 logo’d
OS compatibility: compatible with various Linux* distros
Kensington* lock with base security
3-year warranty