How many acres about do you need fenced in with power ?  Are you tryin to keep livestock in or keep critters out ?  What kind of climate is it where you live ?  
IMO I would get a battery powered fence unit with as many joules as you can afford for this project if your in a mostly sunny climate .   Another factor in the equation is if you go with a battery powered unit , a battery tender charger, a deep cycle battery , and a small solar panel , you don't want to have this set up in a place where you can't see from time to time or some thieves can target you from the back side and steal your set up .
I don't have a pig in there race but the 
Buy the Cyclops STALLION 12V Battery Electric Fence Charger Energizer – CYCLOPS ELECTRIC FENCE CHARGERS    is a good place to start . 
You could also run a battery powered unit and charge battery now and then with a 1000' cord line and  battery charger . 
Or go the underground route like Peter 315 posted .  If you dont have one , can't borrow one might be a good excuse to add a quality premium shearbolt protected sub soiler to arsenal of implements . Just some thoughts on your question .