Wireless 'dumb' sensors

Hi,
I'm trying to find out the feasibility and options for a system of wearable inputs and outputs but without a MC at every location.
i was looking into xbee, Zigbee & RF 2.4Mhz.

Any Advice would be appreciated

Depending on the range you need, ESP8266's might suit. Otherwise, why not go for a nano compatible board with an nRF24L01, it will still be fairly cheap.