TSOP1856 will probably do the job.
It is designed for 56kHz, but will receive 50kHz happily at short ranges (about half the range compared to 56kHz)
I would use that.
Designing your own receiver is a difficult thing to do, and likely to result in a worse receiver than standard TSOP1856.
EDIT: or are you using 40kHz carrier? Your diagram shows 50 kHz, but your text states 40kHz - very confusing.
If you are using 40kHz, then the choice is very obvious.... TSOP1840 or some equivalent that can handle continuous transmission (many IR receivers only handle limited bursts of data - see datasheets).