Rebuild is a good option.
Japan parts will cost you around 50-60k
& machinist 13-15k & labour is around 12-15k
Rest engine oil, filter and stuff. And if any other parts required they will be seperate like spark leads, plugs, distributor parts etc. Or any carburettor parts.
However if you drop the quality to Chinese the cost cut will be slashed by atleast 15-18k from the total. Rest all expenses will be in the range.