@addy
i personally got myself a beetle a month ago...trust me the original engine works just fine...its just that ordinary mechanics cant handle it and theyll giv u false reasoning against it...however there are plenty of beetle specialist mechanics in every city so dont be discouraged.
my car was overheating wen i got it but a simple clean up of the engine did the job.the main reason was the fan was broken.
having fixed that its the most hardy engine ive ever seen.my mehran and city couldnt take the abuse this engine has seen...
as for parts i hav not faced any problem so far...
all parts are available surprisingly cheap and easily.
il advise u to keep the original engine or get a beetle 1.6l engine if u want a swap really bad...PLEASE DONT GET A LARGE WATERCOOLED ENGINE as itll b a lot of hassle making room for it moving the fuel tank.its also rear wheel drive so thatll cause problems.the alteration wil b a headache to complete and a bigger pain to maintain...