So, what do you like? What kind of arena- indoor or out? What kind of footing? Do you want your horses out in pasture with shelter access, or in a stall with turnout? What kind of stalls to you like? I have seen the mesh fronted stalls, and I really like them. I like the ventilation, and being able to see the horse without going into the stall. I would like a v-shaped drop down door on the front though, so they can put their heads out.
I prefer indoor arenas and never really use outdoor rings. If you have dressage riders there I think it's really important that at least one arena is a standard dressage ring size, even if you have to do it outdoors. I want my horse to be outside with shelter as much as possible during the day but inside at night or when it's just too hot or cold outside. And he needs to be able to go out alone or with one friend, not a group.
Those mesh front stalls looks nice, but I don't know much about them. But I definitely like drop down doors - they make things much easier and I think they are safer than half doors. The stalls should have bars to hold blankets unless you have a blanket rack somewhere and probably even if you do. I don't want to have to store blankets in my locker or haul heavy winter turnouts all over the barn.
One of the best things I've ever bought was a stall fan and I think every horse should have one - they help so much in the summer!
What about a dog policy- yes or no? What about a lounge/viewing area?
I like having dogs around, but only spayed/neutered dogs and if any of them cause problems the barn owner should deal with it right away. I'm fine with people bringing their puppies to help make them barn-safe but you need to be smart about it and puppies running into arenas is definitely not okay. All of my experiences with dogs have been very positive though and I can imagine how quickly things can go wrong in other circumstances.
A lounge/viewing area is not that important to me because we have a great seating area in the arena itself. At the same time, if people want to socialize while watching rides they should do it in a lounge, not in the arena. It lets people watch rides without distracting riders or making them feel too watched.
What kind of feed do you want available, and automatic waterers or bucketed water?
Hay at least 4x/day. Grain should be matched to the horse. In performance stables it is easy because everyone can pretty much eat the same thing. It is harder if you have a range of work habits, ages, etc. If I don't like the feed that's being fed I want to have the option of using my own. And of course supplements should be fed if provided. I like automatic waterers.
Round pen indoor or out? How big? I have a 60' right now and I love it- but I have thought of getting another, possibly smaller one.
I've never used a round pen so I have no idea.
And tack rooms? Heated and a/c is a must here in Missouri. What do y'all think of this as a lockable tack place? Could have locker number and name plates on front, and have keys for it? Extra keys would kept at the barn incase yours were lost or forgotten.
Large, lockable tack lockers! And I want to be able to modify them - put up shelves, put the saddle rack where I want it, etc. The ones you posted look perfect. We have extreme temperatures were I live but there is no heating or air conditioning. The barn is insulated which helps regulate the temperature.
It would also be nice to offer storage for blankets, extra tack, etc.