Replacing defunct oil boiler with a new BIASI B10-5 unit, asking for input on circulators, etc.

Hello everyone-

I am soon going to replace a steel constructed oil boiler that failed (incidentally, it was a "newport" by Lars Teledyne, it's quite old and it developed holes in the burner/ blast part of the unit). the new unit is going to be a BIASI B10-5 cast iron boiler, they seem to use a better ("three pass") design that is built well and engineered for efficiency. The BIASI is packaged with a RIELLO burner and also includes a Honeywell 7248 Aquasmart high limit and an immersion well, a pressure relief valve, and a pressure/ temperature gauge... it does not, however, come with a circulator pump.

1/ Would it be best to put on a brand new circulator pump while the system is torn apart rather than using the old one? A Grundfos replacement pump with a check valve is around $100. I researched model UPS 15-58 FC/ FRC from the Grundfos literature as the correct replacement for the old Taco circulator. The Taco is at least 15/20, possibly around 25 years old, but it still works fine... do cast iron pumps run on forever or do they sometimes fail when they hit older age? The Grundfos may be slightly better in that is has a check valve, but not sure if that is worth spending $100... 2/ How important is it to add a low water cut off to the system? I'm not sure if code here requires one, but I read that they are required in Canada. If it's an inexpensive part I should probably put one on, as insurance??

With the RIELLO burner, the BIASI boiler should be a great improvement. I'm not adding anything complex to the system, other than I'd like to put on a tiger loop and perhaps also an ODR control to make the boiler operate efficiently. If anyone has any comments on the BIASI three pass boiler design, RIELLO burners, the circulator, or suggestions on adding an ODR control (would a TACO be a good choice?), I welcome any comments... thanks for reading this post.