The ECT (Engine Coolant Temperature) sensor is located in the thermostat housing on the front of the motor: follow the upper radiator hose (the one that attaches near the pressure cap) -> back towards the motor: where it connects is the thermostat housing.
The ECT sensor is screwed into the right side of that housing here, the connector (should) have a metal wire clip that needs to be removed (with a pick tool) before the connector will disengage from the ECT.
The thermostat is located within the thermostat housing (where the top radiator hose is attached.)
To answer your question, both the Thermostat -and- ECT sensor are located at the thermostat housing block.
re: should I replace - I would be pulling, inspecting, and testing the ECT first, but you know your Sporty better than I do - if original or suspect, (if it was me), I'd be replacing it.. Just remember to clean up any old gasket material from all mating surfaces really good before reinstall. re: brand, I use & recommend STANT thermostat parts here, been 'burned' (pun intended) by no-name / off-branded replacments too many times.. Or source an OEM replacement, if you wish.