i dont know about B5 sohc's hp figures but B5 dohc produces 110hp and in some countries even 130 hp.
but then again, its availability is doubtful.
spectra's engine is quite toned down engine. it has a Siemens ecu and kia has used there own fuel maps. As far as i remember, 1.5BFD has more torque than a dohc B5 [110 hp]
but a stock spectra motor produces 160-165 whp easily and safely when turbo charged.
and yes, 1.8 will be quite heavy but it was just a suggestion.
and i have no idea about daewoo and its engine. maybe daewoo has also borrowed engines from mazda like kia did in early days.
best of luck!