I used a BMW E36 M3 (they have their battery in the boot) battery cable on my Golf when relocating the battery behind the passenger seat. I used a conventional 063 round post battery so the clamps on the M3 cable fitted. Remember you need to up the cable thickness the further away from the starter the battery is, or it will suffer from excess volt drop and not have enough juice the operate the starter.
Not aware of a quick-release system sorry.