The right direction would be to find another dentist in the UK with a different quote. I would really only recommend getting work done abroad if your talking about the USA/Canada or Australia or New Zealand. Its worth noting that dentistry is practiced differently to some extent in virtually every country standards and quality vary. If you have the type of work your describing done abroad there's every chance that it would be carried out to a high standard and probably cheaper. BUT if for instance
1) Your porcelain veneers fracture (they are brittle!)
2) Your crown margins are inadequate leading to periodontal/gum disease
3) The tooth/teeth become non-vital/die off as a result of crowning (1 in 3 do anyway!!) and you need root canal treatment
Then DON'T be surprised by it or be shocked if the cost of repair (if possible!!!) isn't far greater than your original quote.