race track timing with laser and PIC

I'm building a timer using PIC for small race track for diecast size cars. I've been researching laser and infrared sensors on the internet. Basically what I'd like is a laser/infrared beam that is narrow but tall. The beam source and recieve will only be 5" or so apart. I would like a device with a controller that goes high (or low) when the beam is broke. any suggestions/recommendations?

also, any recommendations for a development board with a pic with a lot of timer compare options/interupts and with an altera logic device?

thanks

Perhaps a hall effect sensor would be more efficient/easier to implement?