As a Chartered Accountant, I would say that the VAT route is the easier to do, IF, and only IF, (IFF, if you're a mathematician) you are going to be self-employed/freelance. With UK VAT at 20% , it ain't a trivial amount.
Reclaiming a tax allowance against your income tax is way tricky (technical term there). It would likely involve investigations from HMRC so you would need to ensure that you are within the regs. And those regs are a grey area and it can quite often depend on the whim of the individual Inspector. And that's when you need a professional behind you.