I was a bit worried about the signals and the length of the cable so only extended by 1m using the following cables:
USB3.0 Extension Cable 1M,NeeKeons USB 3.0 A Male to Female Lead 5Gbps Data Transfer Cales (1 M)
HDMI Extension Cable 1M, POSUGEAR Nylon Braided HDMI Male to Female Cable compatible with HDMI 2.0a/b, 2.0, 1.4a (Ultra HD, 4K, 3D, Full HD, 1080p, HD
Both nice quality, both work well if you only need a wee extension.
If you need DP to HDMI, make sure you get HDMI 2.0a and DP1.4 otherwise your headset will not work or run at 60Hz...