You have a fun and exciting time ahead Julie,
I would say from my experience that thats the best way to do it, a door at the front and a door or a window at the back, my farrowing arks have a door at the front and a large window at the back with a cover which can slide, this has many benefits when they are farrowing because you can keep a close eye on her while she is farrowing without having to go in with her and also keep a very close eye on the piglets without disturbing them or the mother, this also makes a good ventilation system in the ark which is important and will help prevent the piglets getting pneamonia! This has worked very well for me and my sows and worked well for a new gilt that we had, she was quiet a nervous pig, so it enabed myself to make sure she farrowed ok without her knowing i was actually their, I could also keep a check on the little ones without her knowing too.
Watch the little ones though when they start venturing out, you may need a a strand of electric fence quiet low to the ground to stop the little ones escaping, I just had stock netting to until my frist litter arrived, they are very adventurous!
Good Luck with them and Enjoy.