I missed out on the Asus motherboard recently :( but instead found this. Looks a good spec and price:
Intel Thunderbolt 3 Certified Motherboard - Powered by Intel's own Thunderbolt controller the new Thunderbolt 3 protocol, which is available over a USB Type-C connector on the back I/O of the GIGABYTE Z170X-Ultra Gaming, brings an unprecedented single-wire bandwidth of up to 40 Gb/s -- twice more than the previous generation of Thunderbolt! This incredible increase in bandwidth is also accompanied with support for different protocols such as Mini DisplayPort 1.2 and USB 3.1, which is backwards compatible with USB 3.0 and USB 2.0, opening up a world of new possibilities.
Intel® Thunderbolt™ 3 Certified Motherboard
Supports 6th Generation Intel® Core™ Processor
Dual Channel, Non-ECC Unbuffered DDR4, 4 DIMMs
Intel® USB 3.1 with USB Type-C™ & PD 2.0 100W Support
2-Way SLI™ & CrossFire™ Multi-Graphics Support
NVMe PCIe Gen3 x4 22110 M.2 Interface & U.2 Interface for Intel® SSD 750
Best Support for 3 Intel® SSD 750 Devices in RAID 0
2 SATA Express Connectors for Up to 16Gb/s Data Transfer
Intel® GbE LAN with cFosSpeed Internet Accelerator Software
High Quality Audio Capacitors and Audio Noise Guard with Ambient LED Trace Path Lighting
Ultra Durable Metal Shielding over PCIe and DDR Slots
Ultra Durable Anti-Sulfur Resistors for Longer Lifespan
Ultra Durable Anti-Rust Rear I/O Connectors
Dual Hybrid Fan Headers with Precise PWM / Voltage Control for Water Pump & Fan
GIGABYTE UEFI DualBIOS™ Technology
APP Center Including EasyTune™ and Cloud Station™ Utilities
Rear Panel Mini DisplayPort-In for Future Feature Upgrade
This is £140+ elsewhere!
Lowest price according to camelx3! See post 1.