looking for a bit of advice from you toyota experts

i own a 94 diesel toyota liteace. its a 2.2 with a 3ct turbo engine with a new feature... a siezed bottom end. looking to replace the engine, can do it myself just having a bit of trouble finding one. what im wanting to know is if i cant find a 3ct from a lite/townace do i have the option of using one from a different car? previa etc.. i have read these have the cylinders horizontal though so would this mean it cannot be used in a liteace? also would a 2c from an earlier liteace go in without too much hassle? i wouldnt mind downgrading to a 2l.. any advice would be greatly appreciated! cheers