18x18x12 or 12x12x18 for Gargoyle Gecko?

[HeckinGecks]

I just asked recently on another, busier, gecko forum but I love some variety so let's ask here too.

I've been interested in getting a gargoyle gecko for over a year now, and I currently have the opportunity to get an exo terra for only $40 which seems like a wonderful deal to me. I have two options, however, a 12x12x18 or an 18x18x12.

As far as I know, if I got the 12x12x18, I'd have to eventually upgrade to an 18x18x18 as the gecko grows up, but would I have to do that for the 18x18x12? Or is that perfect for a garg, since they're not as high climbers as Cresties, and tend to stay lower down and wider out? Which one do you recommend me getting?

Thanks in advance for any advice you may have

 

[Jetfire]

My Gargs are all over their enclosures. They utilize EVERY inch of space in there. When I used Exoterras, I went with the 12*12*18 for juvies/subadults, and went up to 18*18*24 for the adults. I built an enclosure myself (marine-grade 1"plywood, screen panels, buttload of polyurethane to waterproof) that's 18*18*30, and it's served me well for years. I use mostly Sterilite tubs now, because my girlfriend seems to be a freaking Eskimo, and the AC was just drying the Exos out too fast.