What meat breed of pig did you get in the end Tirdu?
There is a good oxford, sandy and black breeder in cilcennen (sabrina, who in the past has also won prizes for her pigs), we are fattening one up ourselves from her, and a welsh pig from andrew in Llanon (his pigs have won several prices at royal welsh etc).
Personally i really do like the temperment of the adult pigs of the above two breeds, they both fatten up pretty quick yet are still rare breeds, have good mothering skills, and in general are well tempered at farrowing and up until weaning. If you have the right kind of system and feed you can get both to around 60Kg in 24 weeks, and the Welsh well you can get them that big as young as 18 weeks, good little turnover if you have the land.
Whilst another personal favorite is the Large black, lovely docile breed but do take a long time to fully fill out and make a respectable looking bacon pig (wouldnt use this breed for pork personally, its like using a Berkshire for bacon they werent orginally designed for that, however if you crossed the two thats a different matter), unfortunetly the nearest large black breeder is 10 mins away from builth wells.
Are you getting the GOS from John near Abermeurig?