Its always exciting when you start out! I would add a word of caution though. Pigs are highly sociable animals and need to be kept with others at all times. You could have two breeding girls, or you could have a castrated boar as a companion for her. I would also be mindful of the time of year it is and the ground conditions, you might be suprised at how distructive pigs are and change your plans in a few months.
In your sitiuation I think it might be an idea to raise both pigs for yourself and see how it goes before going down the breeding route. If you decide to breed, you are probably better off buying an in-pig sow who has farrowed before and is a proven mother. Young inexperienced sows and a first time owner really aren't the best combination.
Good luck with them, Pigs are wonderful charicters