Building an Indoor Ring - any suggestions??

One of my clients is considering building an indoor arena on their property... they want something safe and economical. There seems to be many to choose from, but overall there are two main types - coverall types and solid steel type buildings.

What do you reccomend, who do you reccomend? I've explored many types:

www.wecover.net/

www.megadomebuildings.com/

www.cover-all.ca/ www.norseman.ca/

www.britespanbuildings.com

and more!

There are so many to choose from, and all of them seem have nice designs - any suggestions? Let me know, you can contact me through this link!- http://www.lfequestrian.com/Contact.php