CCTV camera? Sounds a bit of a weird scenario.
Ill come and do it for €6000
Canon powershot are decent.
Go pro no good for what you are initially trying to achieve.
horizontal or vertical 'tunnel'?if horizontal a Gopro on a small trolley (skateboard) pushed using a long rod should work, mount lights on trolley and bob's your uncle.As you've said, a professional will only do similar, but worse.
I'm no expert but this Canon looks good.