how would you repot it with one of those?? it would be hard to get the root-ball out.

Good question, maybe something similar would be good but that has a wider opening at the top

I don't think either the top photo or the bottom photo on that page is a 'planter." They are vases, not meant to sustain plant life, but to temporarily hold it. The bottom one is definitely an Ikebana vase mean to hold cut flowers. The top photo appears to me to be a hollowed stone, or ceramic container without drainage--hence no feet on the bottom that would allow that to happen.

The closest you could probably come to a functioning plant holding pot in bonsai circles would be a drum pot, or "accent" pot mean to plant miniature perrenials or annuals in. Supplies for those are as close as doing a search on "bonsai container" or "bonsai pot" on a web search engine.

Would you like something more like this?

http://images.google.com/imgres?imgurl=http://www.bonsai-nbf.org/assets/images/02potcomp/IMG20sm.jpg&imgrefurl=http://www.bonsai-nbf.org/nbf/potcomp2002/02finalist.htm&h=256&w=384&sz=13&tbnid=LKpPaC9af_sJ:&tbnh=79&tbnw=119&hl=en&start=150&prev=/images%3Fq%3Dbonsai%2Bpots%26start%3D140%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN