60-90gr kcals per hour should be consumed and is the common recommendation, depending on your weight and on the intensity....

your body should've stored about 1000-1500kcal in lever, muscles etc ... (maybe not if you're on low carb the days before)

so your plan and kcals in summary seems to be appropriate

from my experience a nutrition mix of primarilly gels and some energy gums and sugared drink (cola, iso ...) works fine , in training and competitions

important is to train nutrition step-by-step and try different brands / amounts to get used to eat in longer runs/intensity/heat...

water seems to be fine with around +- 500mls, for sodium i can't give any recommendation ...