Water tank replacement / repairs

[FE2015]

About 7 years ago the water tank on the roof of our holiday home in Lefkosa split and spilt water all over the corner of the building.
Since then, we have had no water in the building

As we haven't had to time to holiday in TRNC yet - we haven't tackled the problem. There is also the cost issue - which has been putting us off.

Now we need to start putting things in order I am trying to find out as much info about what needs to be done to fix it.

I believe the tank is a very large metal one (not sure about size really).

Can it be repaired or should it be replaced? It is at least 15 years old.
If a replacement is needed - can anyone recommend what is the best tank to replace it with? Metal or plastic? that will last the longest and won't burst or split due to corrosion or dodgey valves?

Also, can anyone recommend someone who is qualified to do the job for the right price? And how much should a job like this cost including all the parts?
Is it worth bringing parts over from the UK or can they all be found in TRNC?

Any advice much appreciated!!