The previous owner of my car (still on KE-Jetronic (MFi)) took it to NMS in Derby. For the power it runs it actually drives very well and so far it doesn't seem too horrific for a K-Jet car. You have to remember that not many people will deal with K-Jetronic systems. If I am honest, there are probably more people out there dealing with SUs, and definitely Weber DCOEs and modern ECU setups.
Ford were not the only people to put a K-Jetronic setup onto a turbocharged engine, Porsche also did with the 924 Turbo and 924 Carrera GT/GTS. With that in mind (and seeing some people tune up with good results up to around 260BHP) I would be tempted to check out people potentially in that sector. EMC Motorsport in Saltley, Birmingham (
www.emcmotorsport.com) are worth a shout (they have worked on all sorts and made a very fruity CVH engined Fiesta XR2 back in the day). Ask for either Kevin or Alex and say that Chas sent you

.
I would possibly recommend NMS but I have not dealt with them myself so am not in a position to comment. Their website would suggest that they know about how to go about setting up a car with a K-Jetronic system.