It all depends really - Do you feel like your losing out on not having the UK Spec with CC and possibly alarm (if yours is missing an alarm walk away)?
If so then the person you eventually sell to may feel the same way, also not having the CC could narrow the buyer when you eventually sell.
Me personally, I wanted CC and would never buy a car without an alarm (bear in mind this will affect your insurance if it is missing).
You have a huge choice of cars available, don't rush into buying if you have a nagging doubt......it will eat you up inside if you buy something you later regret!!