@sayedgulhassan
Bore and piston of .50 sounds that ALREADY OVERHAULED so OK;no issue
Better go for Full overhaul including bore piston rings crank head work gaskit etc.
Also collect all A/c parts at one place & take pictures. I think u better leave that work for summer. I will give u better alternative option with SANDEN compressor. I have learnt lots of lesson in A/C works & compressors types so dont want any other to lost his hard earned money.
Best of Luck for your project.
As said earlier, keep close eye at this stage.Specially look for Roof work
& after completion, 1st thing u do is Takaful Insurance of your car to minimize your burden & headache