I have a GC in my NC1 bought pre-owned for a think £250…
It had no fixing bolts so I badgered the rollox off Grant and with constant pestering, waited about 3 months.
They were just hi tensile steel nuts and bolts
which if I’d known, I would have picked up locally.
Anyway, nows it’s fitted (12+ months since), it’s all good.
Thankfully, I’ve not needed to test it’s track or road integrity but it firms the chassis up a little too 
Not sure about the whole range, but the GCR bars are Motorsport UK (formerly MSA) certified. From what I’ve seen most other bars aren’t.
Having lived with mine for a good while now, I’m very happy with it. I’d just recommend buying from Bofi or another reseller rather than going direct.
tbh I have the cybul stuff, excellent fit in my car, minimal cutting for the trim. i didn’t test its crashworthiness as well, nothing was missing and its was delivered when I was told it would be delivered - in a month (as it was a custom order because I wanted a matt black instead of the gloss bofi usually order them in)