If I were a 997 owner in the UK without PSE, I would seriously consider getting it retrofitted. The problem with such things is that OPCs in the UK charge high labour rates. I actually think it would be much cheaper to go across the Channel for the day, get it fitted in France, Belgium, Holland or Germany (plus do some nice duty free shopping) and then come back to the UK that evening.

Just my suggestion, but it's no secret that labour rates in the UK for any skilled worker are ridiculous.