Any water heaters with built-in exchanger?

I've been looking for a reasonably priced propane fired WH with built-in heat exchanger for DHW and closed circuit heating, did I miss it? The BW PDX2 and AO Vertex have side taps, but I would need additional flat plate exchanger to hook into my heating loop. Is there a model that includes the internal HX for less than $2000?

Thanks,

Not for less than $2K.

You might find an ~80% efficiency BW Combi-2 for around $2K but at current propane prices it's well worth going to a condensing system, even if it's a DIY design off a Vertex.