I'd say Berkshire definately for pork, they're a smaller breed and would take a longer time to reach bacon weight than the rest.
I usually aim for around 80Kg liveweight for pork (you'll get approx 40kg of meat) and around 100Kg plus for bacon - but as hughesy says you can make great bacon from smaller pigs, the eye of the bacon is just smaller. Check with the abbatoir your going to use and see if they have any weight restrictions for pigs (some only do up to 85kg)
If you're feeding 1lb of food per month of age (per pig per day, split into 2 feeds) then your porkers will be ready to go around 6 months old and the baconers around 8-10. If you're giving less pig nuts and more fruit & veg then they might take a bit longer.
The only issue I see is with the size of their pen - it's just over a third of an acre
We've only ever raised a maximum of 3 pigs to pork weight on this kind of area. You might find that the ground becomes very wet and muddy, especially with 8 and taking some on to a bigger size. Do you have another area you can move them to if this happens ? If not, I'd be tempted to start with less pigs 'til you see how it goes.
HTH
Karen