Engine transfer M13 for G13BB

Hi All, I hope you can help. I am in a terrible dilemma. My Jimny engine blew last week, very disappointing, but I may be partly to blame. We won't go into that. The mechanic is telling me to dump the engine and get a new one but it sounds like it is going to cost me over $2500 to do that. Mine is a 2001 softtop and I love it and want to keep it. It has come to my attention that there is a rolled 2006 hardtop for sale for around $4000. It is still in working order, in fact the girl is still using it as her vehicle. Now I am thinking how nice it would be to put that engine into mine but I've had a lot of advise saying NOW WAY, you can't replace a G13BB with an M13. Fair enough, swapping just the engine is not possible but what if I swapped everything?? Gearbox, computer, injection, etc etc. What would I have to swap? How big a job is it going to be? There after I sell the left-overs as parts and make a bit of the difference up. What do you say? Anyone out there with experience here ?? Appreciate any advise. Thanks