They (Z & X) are in Agapinoros St, known locally as Russian Road, or Mr Chicken St.
To find: as you come down hill from the Police Station towards the habour, after about 700-800m you will come to a set of traffic lights which has an art gallery on the LHS and a boatyard on the far right. Turn left there. Z & X is about 500m down this road (Agapinoros St) on the RHS.
We bought 2 from Florida pools just before the coral bay turnoff in November last year can't remember how much but they also had second hand ones available