Does anyone out there have knowledge of Seisco brand(seisco.com) of low temp electric boilers that they market for residential radiant/water heat? Seems like a decent product with some nice conveniences and a gradual run-up of the electrical load when the unit kicks on. Prices also seem in line with other electric units of the same size.

Thanks in advance for any responses.

Seisco is a flash electric water heater, not approved as a boiler.
If you are looking for a true electric boiler you may look at Thermolec, or others.
There is a substantial difference in requirements when certifying Boilers or water heaters in USA or Canada.
A good quality boiler will last considerably longer than a water heater and is design specific.
Dan