The one I am waiting on is on backorder. It's the CC25-mod. I was told it is borderline on being big enough but the price was right compared to the others I looked at and I figured insulation would make a big difference. You just need to make sure it has a Ti heat exchanger.
http://www.aquastealth.com/
This place only sells to distributors but has all kinds.
http://www.pacificcoastimports.com/
SS