component choice timing system

Hello,

for a school project we must make a time registration system,
we know my-laps and other kind of company 's have systems but they are very expansive.
we've got the idea that we use the same system as a registration system for a company using rfid.
and a infrared gate for the timing.
and a wifi or ethernet link.
i know arduino has the most of this component's
but we don't know wich specific components we must use.
sorry for my language problem.

RFID usually only handles one transponder at a time so would not deal with a group of people standing nearby all trying to register.

sorry peter, it is about a horseman and a trailer they must do a parcour.
so there's one men at a time.