wow sorry to hear that - timing belt could mean valves have met pistons and you have many curved items that are supposed to be straight
I wouldnt try and dissuade you from an engine swop however you would def need a remap plus if you went 2.5 I think you would end up having to change everything to do with air coming in exhaust going out and the fuel supply.
I would consider a 2.0 change but again map, fuel system all may need looking at