With regard to water, you need to use something that is relatively 'immovable', or the pigs will just throw it around for fun. We use galvanised water tanks, but have also used belfast sinks etc. Buckets need filling 20 times a day on a hot day as the pigs keep flipping them over to wallow.
With regard to food, I've tried a few types of food over the time we have had pigs, and in general they will end up eating anything, although they may be slow to switch in some cases.
I currently buy my food for £250 a ton / £125 half ton, although it comes lose, in a half ton sack. £150 for bagged food is pretty good going. I'm also in South Wales.
Rodents fecking love pig food.