Have you tried: PhysioFirst Physiotherapist Directory

and look under sports injuries for someone local?? Might be worth ringing them and asking if they specialise in that area. I agree a podiatrist is probably the way forward, if yours is a biomechanical problem then custom made orthotics are probably your best bet....pricey but may be worth it. See if you can get referred to a specialist podiatrist, there is obviously an underlying mechanical cause as to why you are suffering with this.

Other thing you could try is myofascial release- it's meant to be very good for Wikipedia reference-linkplantar fasciitis. Plenty of these guys around too....