Hi Scotty,
I use this IR pair: http://arduino-info.wikispaces.com/InfraredBeamPair
The transmitter just needs 5V and is packaged nicely. The receiver works well under most lighting conditions. In direct sunlight you need to put it in a blackened tube to get longer range.
This has worked well for people / animal detection and object detection across a 4 foot path on conveyer belts in a warehouse.