Motocross Racing Solution Needed

I am looking for a company, preferably in the UK, that I can discuss my requirements with. I want to detect and identify motorbike racers as they pass over the finish line each lap, using passive RFID tags. There are often 5 or 6 bunched together as the sport is off-road motocross. Speeds are around 50 miles per hour. I have a found a small Finnish company that does software but the supply of RFID equipment is throuigh him and I want to deal diect with an RFID supplier in order to know what can and can't be done in this sphere.
 
Hope you can help.
 
Thanks,
Richard