[Cpl. Hicks]

Also, our cage can double as a stage:-)

The base is elevated and square so it can be modified to carry a ring as well. I guess You won't be needing any significant elevation but still... Make sure that the base is sturdy/rigid/compact as hell; our cage doesn't bulge a millimeter without being bolted while just recently I've seen cages at local events that were swinging left and right due to poor basing and crappy mounting of posts/fence.

I'll try to get hold of the blueprints and see whether there is anything one should pay special attention when building a cage. As I haven't been involved in the building process I don't know the obstacles that were encountered or problem presented.

A I have already stated the key issue is to keep it simple installation-wise; even if you plan never to move the cage build it as if it is going to be on the move every week. Avoid thousands of bolts, screws, small parts etc. Interconnecting parts (I somehow doubt your cage will be a single-piece construction) should be of a size that is convenient to transport and manouver with (if any part needs more than two adults to lift/carry it it's to large/heavy) but not to small (you don't want your cage looking like a puzzle while disassembled).If the guy who is building it is any good, he'll make sure that the bolts/screws etc are in the right places in the right amount. We can fit all the bolts etc. needed for our cage in a plastic bag (albeit a large and durable plastic bag but still a bag:-).

It is really hard to give any advice regarding feasibility of building a cage as opposed to buying one as you're in Japan and I have no idea how the prices of labour (craftsmen) and material compare.