...but can't seem to find any here in the states. Any suggestions for sources or alternatives?
I *think* what you're looking for is either a Kamado or BGE (big-green-egg).. I've got a #7 (or K7 as we call it) Kamado that is thick ceramic and weighs in a 600# or so.. They've got smaller ones such as a #1, #3, #5, #7, or #9 (#11 is in the works).. The smaller they are the lighter they are.. I've had mine since early April and love it -- it's used about 3-4x per week, doing everything from low-n-slow cooks of ribs, pork butts, etc or fast grilling of steaks or even Pizza's at 600+ degrees.. The Kamado's are generally cheaper than the BGEs when you discount the add-ons. BGE's can be found at your local BBQ Galore store if you've got one..
I'm not affiliated with either company, but am a happy owner of a K7..
Here is a link that might be useful: Kamado website.