This is only my opinion, but I wouldn't advise a novice to take on wild boar
They're mental
and definately NOT the easiest or nicest to keep. You need to have a dangerous animal licence and much more by way of fencing than 3 strands of electric - I'd always go for tape rather than wire too - it's easier for them to see.
Something floppy eared is likely to be a much more docile pig and ideally suited to a newbie
Something like a Gloucester Old spot, Oxford Sandy & Black or British Lop would be a much better choice and they would be fine with just 2 strands of tape. If you've got an acre that needs rotivated, probably 5 or 6 weaners would be needed to turn that over in the length of time it takes to get to slaughter weight, or split it into smaller sections and move them round as they clear it. They will effectively plow, fertilise and get rid of all the roots for you - but they will trash the ground
Given 6 months to a year it will recover though and should be fine for cattle/sheep.
Kune Kunes (my fav pigs
) will do well on grass and graze rather than root, if you were keeping them they would only need around 1lb of food each per day, plenty of grass and a bit of fruit and veg to keep them happy, healthy and fatten for slaughter. But they do tend to be 8-10 months old before they're ready for slaughter because they are quite a small pig. For all other breeds of pig you're looking at 1lb of food per month of age every day up to a maximum of 6lb per day, so starting with weaners around 8-10 weeks old they'd need 2 - 3 lbs of food each per day (split into 2 or 3 feeds)
Best thing I would recommend is to find someone locally who keeps pigs and go along and talk to them, most of us are only too happy to show off our piggies
What area are you in ? Someone here might be able to help you.
Hope that helps,
Karen