Indirect water heater and control

JTM

I have a peerless boiler with an internal coil that provides hot water. I have hard water (12 – 13 grains of hardness, 204-221 ppm) and the coil calcifies every 4 years or so (at $800 a pop). The local heating company is recommending an indirect water heater to solve the problem. A couple of questions:



1) Will this truly solve the problem -- or is there a better solution? Will I still get calcification within the indirect system itself and/or piping?



2) They are recommending the Buderus S32 (S120) and the Crown Megastor 40 at over $400 more -- are both capable units? is the Megastor worth $400 more?



3) Should I replace my older control box with a "cold start" model ($330 more) or a Beckett Aquastart ($398 more)?



Thanks so much