We are building a pole barn at our new house. We have one horse right now and are planning and getting a mare and foal set next year. My husband and I ride everyday and we live right next to a canyon we can ride out our back yard and up the canyon any time we want. We are planning this pole barn and seeing how big it needs to be. Any advice? We need to stay in a budget of $300. We have already spent $90 and bought 10 sheets of plywood. Would a 8X10 be big enough with an acre to go on whenever they want and with being riden almost everyday?