First of all you cannot use remote control receivers, which output digital signals, instead you need simple IR diodes and analog amplifiers for the determination of the IR intensity. Amplifiers are almost required, because the receiver diodes produce very low signal levels.
As already mentioned, IR light is reflected by many surfaces (walls...), so that it will be hard to distinguish reflections from direct beams. It may help to chose IR wavelengths which are absorbed by air, so that reflected light will be significantly darker than direct light. That's another reason for not using IR remote control parts, which use a wavelength that is not absorbed much by air.
Eventually you can use a rotating mirror on top of your robot, like a radar antenna, to get a 360° profile of IR intensity. Then the direction to follow is determined by the angle of highest intensity. A rotating receiver is hard to construct, because it will twist and break any wires in continuous rotation. But it may be possible to rotate an receiver back and forth, so that the wires will not be wound up indefinitely. Once the IR source is located, the receiver can cover a small angle, just to find out when the sender is moving to the left or right. It may be a nice visual effect when the robot first scans the entire environment, and slowly narrows down the scan angle towards the recognized target. Wait --- gotcha! 
Furthermore ambient light should be suppressed, that's why remote control is based on pulses of a certain frequency (38-40kHz), which allow to selectively amplify only that frequency. For your project it should be sufficient to suppress DC signals, by using an AC-only amplifier (with a capacitor on its input). Then the sender diode(s) should be powered by a pulsed signal (>1kHz), not by constant voltage or current.