ETOPS aircraft have as standard equipment which is supposed to be more reliable than non ETOPS a/c. However the fire suppression/containment capability of an ETOPS a/c relates to cargo areas only (in fact ALL long range a/c need to have containment/suppression which relates to alternate/diversion times more an EROPS than an ETOPS requirement). The logic here being that if the fire is in the cabin/flightdeck then crew can attempt to extinguish it. Cargo areas however being inaccessible require automatic or semi-automatic systems.
In the case of a/c certified for 180 ETOPS then the cargo containment will be 180+15. For an a/c like a 767 this requires 3 bottles of extinguishant. The first is fired by the crew should they get a cargo fire warning. The other 2 are fired automatically after a set time delay such that the cargo environment would be unable to support a fire for the pre-requesit time. In the event that the a/c lands well within the 180 timeframe then all the remaining bottles are discharged on touchdown.
As far as I am aware (though I MAY be corrected) the engine fire extinguishing capability of ETOPS and non ETOPS a/c are the same.