PC to Arduino wireless link (low latency)
5 bytes (8 bits) at 1kbaud (1000 Hz) means that the payload is 40 bits and this with my simple maths implies a minimum latency of 40 milli seconds. Given that the payload will need to be packaged like this....


Preamble to lock-in the receiver possibly as low as 24 bits)
Header (address of the receiver possibly 8 bits)
Payload ( 40 bits)
Error check (16 bits)


Total number of bits is 88 bits and at 1kbaud this is a latency of 88 milli seconds just to receive and check the data is valid.

Going at 10kbaud means a latency of obviously 8.8 milli seconds.

This device can transmit at 115.2kbps and has an output power of +8dBm so is a more likely contender and here is the matching receiver module: -



I've not gone into looking at these in any technical detail but they do seem the sort of module to use. They are FM too so there's a couple of dB more resilience for the same transmit power/ distance compared to AM.