The EN1070K is part of Zotac's gaming line of ultra-compact PCs, but don't let its minuscule footprint fool you. It offers the current Intel Kaby Lake Core i5 processor, an NVIDIA GeForce GTX 1070 GPU and can accommodate up to 32GB of RAM. That's more than enough processing power to run a VR setup such as the Oculus Rift.
There's no word yet on when the EN1070K will be released, or for how much. Given that the last generation E-series cost around $1,500, you can pretty safely bet the new one will retail for roughly the same, depending on the specific components you select. So even though it may be small enough to fit into a VR backpack, the EN1070K's price tag may be too big to fit into your budget.