I love my turkeys, they're super personable and funny birds!
As for space, are you saying your coop is small, or your yard? And how many do you plan on raising for FFA? You could get by with a medium sized coop and run for just a couple, especially if you free ranged them for a little while during the day. Ours mostly free range. If I need to put them up for whatever reason, I just whistle and they come running, then they just follow me into the coop and I shut them up. Easy peasy.
Do you plan on mostly free ranging them? If they're only using the coop to sleep, you can skimp there a little. If you won't be free ranging, the recommended amount of space is 6 sq ft per turkey, and 2 ft of roost space per bird. You probably could do a little less if you plan for a good sized run.
If they'll be free range, I think I'd just go up with their coop, make it more tall than wide. Make enough room so each bird has 2 ft of roost space and a place for their feed to stay dry. Mine pretty much just sleep in their coop at night. Its really large, it used to be an old hog pen and has several large breeding stalls with a walkway in front of them (probably 50x100), and they're hardly in there at all. They share that space with 16 guineas and they all pretty much head in just before dark and stay in until I open the door in the morning.
The only issue, if you choose to cut space in the coop, will be if there comes a time when you have to lock them up (like, say, if you have an issue with a roaming dog or they're wandering into your neighbors yard). If you have to keep them locked in for a while, they might get testy without a lot of room.
My advice would be to to make your coop as big as you can afford to make it. Or maybe start with a pair or trio instead of 5.