Burnham Megasteam + HTP Superstor Ulta 60 - great combo?

@mcpm89 , we do NOT discuss pricing on this forum. Obviously you failed to read this:

https://heatinghelp.com/forum-user-manual

I'm not a fan of using an indirect with a steam boiler. There is too much corrosion going on with the boiler and piping that it will cause component failures at a much higher rate than usual. You can do HX, wye strainers, etc to help protect the indirect coil but then those devices plug up and fail. I have stopped doing it that way after i had these issues pop up and it also has happened to friends of mine in the industry too. it also could be because i'm up in the northeast where steam boilers get chewed up and spit out by our water.

I recommend using a steam boiler with a tankless domestic hot water coil. That way, you isolate the steam boiler water from the indirect water heater loop through a heat exchanger arrangement. The wiring can remain essentially the same. You would just need to add a 30 PSI relief valve and an expansion tank on the indirect side of the system, because that portion becomes a closed-loop system heated by the tankless coil in the boiler.

With this setup, the boiler can go cold in the summer when there is no call for domestic hot water or steam heat if you wire the system properly.