After HIGH HEAT!! converting to M13AA

Hi all,

i have my Jimny 99 with G13bb engine
i was in desert "1 car" and the tempreture went up so bad and all water i got was finished........... the tempreture reached around 120....... the rediator plastic head box exploded......... cylinders now are full of damage.......... at the same time i allready got a problem with my A/T gearboox and i was about to change it.......

NOW

im thinking to renew the current engine by Latheing the cylinders and change the pistons after latheing....... but im afraid of the piston matching after the lethe specially that i use the car in offroading. (beside changing the gearbox) but the gearbox i found here is for the M13aa engine (the DOHC) ...........and i dont know if theat gearbox will match with the G13bb engine or not.

and i dont know if any modification is needed to convert from g13bb to m13aa

OR

should i get the gearbox with its M13AA engine to prevent the head ache


i need your detailed advice............thanks in advance