Personally I ONLY like cast iron tubs... I know acrylic is very popular but after years of use (or if someone uses comet cleanser a time or two) it's more likely to show its age. Cast iron IMO holds up much better.
Here in the states Home Depot has the Kohler Villager cast iron in white for something like US$300. Volume speaks! That's a great deal if you need a 5 foot alcove tub with an apron. They have left and right drain.
If you can't spring for the iron tub, as I said I personally wouldn't screw with an acrylic... there are places that can come to your house and repair those enamel tubs. I had it done once on a rental I owned... worked real well... no one would ever notice the repair.