have noticed my 90 doesn't seem to be getting hot over the last couple of days(maybe its just me getting funny with all the snow and stuff), radiator doesn't feel overly hot to touch, heater doesn't seem to be getting toasty

....its not using oil or coolant (still looks green and ok) so thinking its time to change the thermostat (symptoms don't seem to be head problems from what I can see. Have cleaned out the heater sensor under the drivers kick panel and will see if both hoses are hot after a drive tomorrow.
would it be betterer to fit a lower temp one instead of the stock 82 deg one?, are these available from Toyota or do I have to go after market?. Any idea of part number?