The Ir Led are fixed because are fitted to an elevator door.
And both RX and TX led have 1 or 2 meters long cable to connect it to the PCB.
Because the cable for the receive led is long get a lot of noise from the environment.
I tried to make a schematic like the one below and it got a lot of noise from the environment.
The IR transmitter have 150mA current consumption.
If you need any other information please ask me.
The amplifier as such is O.K., you would want a selective filter tuned to the Tx carrier, as already mentioned. But most likely, it's no good idea to connect the receiver through a long cable. Industrial sensors have the amplifier mounted to the receiver for a good reason. If you try anyway, a screened cable, screen preferably separated from signal return would be needed.
You should also consider, that a good optics is the best amplifier.