Lets separate the facts.
Nito is marketing gimmic. Nothing wrong with it but I don't think it worth the cost given air is almost 80% N2 to start with. You can learn more HERE
The cracked valve is a real red flag. This simply should NOT happen on a 1 year old unit. ALL the valves should be inspected. I would also suggest bolt in valves as this will essentially eliminate that problem. If the valve was cracked and leaking that was the cause of the tire failure an not a problem or defect with the tire. The valve is less than 1 year old. It is NOT a tire so should not be excluded from your 12 month warranty.
I strongly agree with the other suggestions to get TPMS. You might consider units with a multi-year warranty and replacable batteries. Whatever brand TPMS you get I again suggest bolt in valves to better support the sender.
Not sure why you need to change tires. Have them inspected by a tire dealer that sells that brand. If there was no air loss or tire damage I do not know why you need to replace tires (valves are different matter). Inspection with dismount would make you feel better. Get the inspecting dealer to give/sell you a tire warranty.
The BEST tire to get is one with a National dealership network.
If you feel you need to change tires, you might consider LT235/75R15 LR-D if your rims can handle 65psi as that would give you tires capable of 2335# and you would not have the 65 MPH Max speed limit. You would need to confirm tire clearance.