Well the minimum is 204 (2WD) although even new many were higher than this, you want to see a decent history and whose done the work especially tuning, avoid any car that's been messed around with, excessivly lowered for example or just looks as it's lead a hard life or driven through the local Halfords window!
As said theres nothing wrong with the ignition system, provided it's maintained correctly there should be no problems.
Parts wise can actually be quite difficult as I have found over the years, alot of the parts are NLA from Ford and so your stuck with trying to find new old stock. I use a RS breaker and find him to be most helpful. An example of this is the shocks they were NLA from Ford but got some from the latter. Like at the moment I am trying to source standard springs but there no longer avaliable so I don't hold much hope seen as there is no demand for them either!
To be honest providing you get a decent one there no need why you should need to be concerned about major parts as there strong cars!
Martin