what? are u in nz as well?, what color is the smoke? depends on the color of smoke it can be easy repair to bad damage. anything pull apart wont be cheap u might as well get another good condition engine slot it in. 3s-gte (3rd gen) would be a nice engine to slot in a celica becuase it will fit stright in with little mods. if u want to play a little, make the 3s-gte 2.2L with ur existing 5sfe crank and forged piston and rods

would be very fun car to drive and have heard ppl done that kind of conversion before, havent dont it my self as i am new to 2L world, i have being modding V8 N/A cars till now. anyways, good luck with ur car.
if u are not in nz, i wont know where u can get a engine from... (try yellow page search for toyota wrecker)