£6.50 a bag!!!!!!! I wish! The price here in Orkney has just dropped to £8 for grower feed (25kg bag) and £8.50 for sow rolls. There's a shortage of barley and other straights as well, so mixing our own isn't really a proposition. We're considering buying tonne bags from Aberdeen and, even with the shipping costs (ferry to Orkney, then ferry out to Westray where we live) it should still work out cheaper.
Anyway. . . we feed the regulation 1lb per month of life to the porkers up to a max of 6lb. A 500g ice cream tub (empty of course) is a terrific tool as it holds one-and-a-half pounds of feed.
Don't get too hung up on breed - it's more important to find a seller who is reliable, experienced and willing to offer 'after-sales' advice and help.
And an electric fence is a really good idea, although skittish, nervous young pigs (as they will be when they first arrive) will go straight through it. Make sure there's plenty of feed and nice piles of straw to investigate - they'll soon get the hang of things and so will you!
Have fun.