hey, i built a custom inclosure 5Lx2Wx3H (60x24x36) out of ply plexi and welded wire mesh, just want you to no what your getting into iv now spent n upwards of 700 to 750 on the cage, with a custom warm air humidifer, lighting, hot and cool spots,and of course lots of decorations .... the hardest is the humidity so you will need a strong humidiifier to keep the warm cage humid. (keep that in mind its the most important) also seal your wood inside for sure bc your ply will soak up all the moisture on ya.
now iv only got one ball about 4 feet and he loves climing and exporing his enclosure. if your only gunne keep one building a custom is the way to go its an awsome focal point friends and family are always talking adout it.