Well...

A LED can easily go 100 m if you put an external lens infront of it. Use an old magnify glass and move it away or closer to the led and you will see where it is in focus. (use a red LED and it is really simple to see where you get a nice beam)

The lower mangnify the further away from the led the lens will be.. and the more narrow the beam will be.

Big and bulky? Yes, definatly

Easy to build the receiver since you can use a normal IR receiver that is built to detect modulated IR light.

Laser, for getting a reliable signal you will need to modulate the laser (same as for the led). Some laser modules have soft-start chips and are not that easily modulated.

If you really want to use laser and dont want to modulate it, put the receiver in the bottom of a longer pipe where is it always in the shadow.